Intel 5100 Series Instruction Manual

Dual-Core Intel® Xeon® Processor 5100 Series

Thermal/Mechanical Design Guidelines

June 2006

Reference Number: 313357-001

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reserves these for future definition and shall have no responsibility whatsoever for conflicts or incompatibilities arising from future changes to them.

The Dual-Core Intel product to deviate from published specifications. Current characterized errata are available upon request.

Xeon® Processor 5100 Series may contain design defects or errors known as errata, which may cause the

Contact your local Intel sales office or your distributor to obtain the latest specifications and before placing your product order. Copies of documents which have an order number and are referenced in this document, or other Intel literature, may be obtained

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Intel, Intel Inside, Xeon and the Intel Logo are trademarks or registered trademarks of Intel Corporation or its subsidiaries in the United States and other countries.

2 Dual-Core Intel® Xeon® Processor 5100 Series Thermal/Mechanical Design Guide

1Introduction..............................................................................................................7

1.1 Objective ...........................................................................................................7

1.2 Scope................................................................................................................7

1.3 References.........................................................................................................7

1.4 Definition of Terms..............................................................................................8

2 Thermal/Mechanical Reference Design.................................................................... 11

2.1 Mechanical Requirements...................................................................................11

2.1.1 Processor Mechanical Parameters .............................................................11

2.1.2 Dual-Core Intel Xeon Processor 5100 Series Processor Package.................... 11

2.1.3 Dual-Core Intel Xeon Processor 5100 Series Considerations ......................... 14

2.2 Processor Thermal Parameters and Features.........................................................15

2.2.1 Thermal Control Circuit and TDP...............................................................15

2.2.2 Digital Thermal Sensor............................................................................16

2.2.3 Platform Environmental Control Interface (PECI) ........................................16

2.2.4 Multiple Core Special Considerations.........................................................17

2.2.5 Thermal Profile ......................................................................................20

2.2.6 TCONTROL Definition..............................................................................22

2.2.7 Thermal Profile Concepts for the

2.2.8 Performance Targets...............................................................................25

2.3 Characterizing Cooling Solution Performance Requirements.....................................29

2.3.1 Fan Speed Control..................................................................................29

2.3.2 Processor Thermal Characterization Parameter Relationships........................31

2.3.3 Chassis Thermal Design Considerations.....................................................33

2.4 Thermal/Mechanical Reference Design Considerations ............................................33

2.4.1 Heatsink Solutions..................................................................................33

2.4.2 Thermal Interface Material.......................................................................34

2.4.3 Summary..............................................................................................35

2.4.4 Assembly Overview of the Intel Reference Thermal Mechanical Design........... 35

2.4.5 Thermal Solution Performance Characteristics............................................ 37

2.4.6 Thermal Profile Adherence.......................................................................39

2.4.7 Components Overview ............................................................................43

2.4.8 Boxed Active Thermal Solution for the

A Mechanical Drawings............................................................................................... 51

B Heatsink Clip Load Methodology..............................................................................73

B.1 Overview ......................................................................................................... 73

B.2 Test Preparation................................................................................................ 73

B.2.1 Heatsink Preparation ..............................................................................73

B.2.2 Typical Test Equipment...........................................................................76

B.2.3 Test Procedure Examples ........................................................................ 76

B.2.4 Time-Zero, Room Temperatu r e Prel oad Measu rem ent ..................... .. .......... 76

B.2.5 Preload Degradation under Bake Conditions .......................... .. .. ... .. .. .. ........ 77

C Safety Requirements ...............................................................................................79

D Quality and Reliability Requirements.......................................................................81

D.1 Intel Verification Criteria for the Reference Designs................................................81

D.1.1 Reference Heatsink Thermal Verification....................................................81

D.1.2 Environmental Reliability Testing..............................................................81

D.1.3 Material and Recycling Requirements.......................................... .. .. .. .. ...... 83

E Enabled Suppliers Information ................................................................................85

Dual-Core Intel Xeon Processor 5100 Series......................... ......................23

Dual-Core Intel Xeon Processor 5100 Series ....................................... .. .. .. . 46

Dual-Core Intel® Xeon® Processor 5100 Series Thermal/Mechanical Design Guide 3

E.1 Supplier Information.............................................. ............................................85

E.1.1 Intel Enabled Suppliers...................................... .. ....................................85

E.1.2 Additional Enabled Suppliers .......................... .. .. .. ....................................86

Figures

2-1 Dual-Core Intel® Xeon® Processor 5100 Series Mechanical Drawing........................13

2-2 DTS Domain for Dual-Core Intel Xeon Processor 5100 Series...................................17

2-3 Fan Speed Control for Dual-Core Intel Xeon Processor 5100 Series...........................18

2-4 Processor Core Geometric Center Locations...........................................................20

2-5 Thermal Profile Diagram .................. .................................................... ... ............21

2-6 TCONTROL Value and Digital Thermal Sensor Value Interaction................................22

2-7 TCONTROL and Thermal Profile Interaction............................................................23

2-8 Dual Thermal Profile Diagram..............................................................................24

2-9 Thermal Profile for the Dual-Core Intel Xeon Processor 5148 ...................................25

2-10 Thermal Profile for the

Dual-Core Intel® Xeon® Processor 5110/5120/5130/5140/5150 .............................26

2-11 Thermal Profiles A and B for the Dual-Core Intel® Xeon® Processor 5160.................27

2-12 TCONTROL and Fan Speed Control .......................................................................30

2-13 Processor Thermal Characterization Parameter Relationships ...................................32

2-14 Exploded View of CEK Thermal Solution Components..............................................36

2-15 2U+ CEK Heatsink Thermal Performance...............................................................38

2-16 1U CEK Heatsink Thermal Performance.................................................................39

2-17 1U CEK Thermal Adherence to

Dual-Core Intel Xeon Processor 5148 Thermal Profile..............................................40

2-18 1U CEK Thermal Adherence to Dual-Core Intel® Xeon® Processor

5110/5120/5130/5140/5150 Thermal Profile................ .........................................41

2-19 2U+CEK Thermal Adherence to Dual-Core

Intel Xeon Processor 5160 Thermal Profile A..........................................................42

2-20 1U CEK Thermal Adherence to

Dual-Core Intel Xeon Processor 5160 Thermal Profile B...........................................43

2-21 Isometric View of the 2U+ CEK Heatsink...............................................................43

2-22 Isometric View of the 1U CEK Heatsink.................................................................44

2-23 CEK Spring Isometric View..................................................................................46

2-24 Isometric View of CEK Spring Attachment to the Base Board ...................................46

2-25 Boxed Active CEK Heatsink Solutions with PWM/DTS Control

(Representation Only)47

2-26 Fan Cable Connection (Active CEK) ......................................................................48

A-1 2U CEK Heatsink (Sheet 1 of 4)...........................................................................52

A-2 2U CEK Heatsink (Sheet 2 of 4)...........................................................................53

A-3 2U CEK Heatsink (Sheet 3 of 4)...........................................................................54

A-4 2U CEK Heatsink (Sheet 4 of 4)...........................................................................55

A-5 CEK Spring (Sheet 1 of 3)...................................................................................56

A-6 CEK Spring (Sheet 2 of 3)...................................................................................57

A-7 CEK Spring (Sheet 3 of 3)...................................................................................58

A-8 Baseboard Keepout Footprint Definition and

Height Restrictions for Enabling Components (Sheet 1 of 6) ................................ .. ..59

A-9 Baseboard Keepout Footprint Definition and

Height Restrictions for Enabling Components (Sheet 2 of 6) ................................ .. ..60

A-10 Baseboard Keepout Footprint Definition and

Height Restrictions for Enabling Components (Sheet 3 of 6) ................................ .. ..61

A-11 Baseboard Keepout Footprint Definition and

Height Restrictions for Enabling Components (Sheet 4 of 6) ................................ .. ..62

4 Dual-Core Intel® Xeon® Processor 5100 Series Thermal/Mechanical Design Guide

A-12 Baseboard Keepout Footprint Definition and

Height Restrictions for Enabling Components (Sheet 5 of 6)....................................63

A-13 Baseboard Keepout Footprint Definition and

Height Restrictions for Enabling Components (Sheet 6 of 6)....................................64

A-14 1U CEK He atsink (She e t 1 of 4)................ .. .. ..................................................... ..65

A-15 1U CEK He atsink (She e t 2 of 4)................ .. .. ..................................................... ..66

A-16 1U CEK He atsink (She e t 3 of 4)................ .. .. ..................................................... ..67

A-17 1U CEK He atsink (She e t 4of 4)........... .. ..................................................... .......... 68

A-18 Active CEK Thermal Solution Volumetric (Sheet 1 of 3)...........................................69

A-19 Active CEK Thermal Solution Volumetric (Sheet 2 of 3)...........................................70

A-20 Active CEK Thermal Solution Volumetric (Sheet 3 of 3)...........................................71

B-1 Load Cell Installation in Machined Heatsink Base Pocket -- Bottom View ...................74

B-2 Load Cell Installation in Machined Heatsink Base Pocket -- Side View .......................75

B-3 Preload Test Configuration........................................ .. .. .. ....................................75

Tables

1-1 Reference Documents...................................... .................................................. ..7

1-2 Terms and Descriptions........................................................................................8

2-1 Processor Mechanical Parameters Table................................................................11

2-2 Input and Output Conditions for the

Dual-Core Intel Xeon Processor 5100 Series Thermal Management Features.............. 19

2-3 Processor Core Geometric Center Dimensions .......................................................20

2-4 Intel Reference Heatsink Performance Targets for the

Dual-Core Intel® Xeon® Processor 5148 .............................................................27

2-5 Intel Reference Heatsink Performance Targets for the

Dual-Core Intel Xeon Processor 5110/5120/5130/5140/5150 .................................. 28

2-6 Intel Reference Heatsink Performance Targets for the

Dual-Core Intel Xeon Processor 5160...................................................................29

2-7 Fan Speed Control, TCONTROL and DTS Relationship .............................................30

2-8 CEK Heatsink Thermal Mechanical Characteristics ..................................................44

2-9 Recommended Thermal Grease Dispense Weight................................ .. ... .. .. .. ........ 45

2-10 Fan Specifications (Boxed 4-wire PWM/DTS Heatsink Solution)................................ 48

2-11 Fan Cable Connector Pin Out (Active CEK) ............................................................48

A-1 Mechanical Drawing List.....................................................................................51

B-1 Typical Test Equipment......................................................................................76

D-1 Use Conditions Environment ...............................................................................82

E-1 Suppliers for the Dual-Core Intel Xeon Processor 5100 Series

Intel Reference Solution.....................................................................................85

E-2 Suppliers of Alternative Thermal Solutions for the

Dual-Core Intel Xeon Processor 5100 Series.................................... .. .. ..................86

Dual-Core Intel® Xeon® Processor 5100 Series Thermal/Mechanical Design Guide 5

Revision History

Revision

Number

001 • Initial release of the document.

Description Date

June 2006

6 Dual-Core Intel® Xeon® Processor 5100 Series Thermal/Mechanical Design Guide

Introduction

1 Introduction

1.1 Objective

This document describes the reference thermal solution and design parameters required for Dual-Core Intel® Xeon document to comprehend and demonstrate the processor cooling solution features and requirements. Furthermore, this document provides an understanding of the processor thermal characteristics, and discusses guidelines for meeting the thermal requirements imposed on the entire life of the processor. The thermal/mechanical solutions described in this document are intended to aid component and system designers in the development and evaluation of processor compatible thermal/mechanical solutions.

1.2 Scope

The thermal/mechanical solutions described in this document pertain only to a solution(s) intended for use with the Dual-Core Intel Xeon Processor 5100 Series in 1U/Volumetric constrained, 2U, 2U+ and workstation form factors systems. This document contains the mechanical and thermal requirements of the processor cooling solution. In case of conflict, the data in the Dual-Core Intel Series Datasheet supersedes any data in this document. Additional information is provided as a reference in the appendices.

1.3 References

Material and concepts available in the following documents may be beneficial when reading this document.

Table 1-1. Reference Documents

Processor 5100 Series. It is also the intent of this

Xeon® Processor 5100

Document Comment

European Blue Angel Recycling Standards http://www.blauer-engel.de

Intel

Xeon® Processor Family Thermal Test Vehicle User's Guide See Note following table

Intel

Xeon® Processor Thermal Design Guidelines http://developer.intel.com/ LGA771 Socket Mechanical Design Guide See Note following table PECI Feature Set Overview See Note following table Platform Environment Control Interface (PECI) Specification See Note following table T

Reduction Guidelines for Rack Servers and Workstations See Note following table

RISE

Dual-Core Intel Dual-Core Intel

Mechanical Models (in IGES and ProE* format) Dual-Core Intel

Thermal Models (in Flotherm* and Icepak*) Dual-Core Intel

ProE* and IGES model) Dual-Core Intel

Flotherm* and Icepak*)

Thin Electronics Bay Specification (A Server System Infrastructure [SS I] Specification for Rack Optimized Servers)

Dual-Core Intel® Xeon® Processor 5100 Series Thermal/Mechanical Design Guide 7

Xeon® Processor 5100 Series Datasheet See Note following table

Xeon® Processor 5100 Series Enabled Components

Xeon® Processor 5100 Series Mechanical Models (in

Xeon® Processor 5100 Series Thermal Models (in

Available electronically

www.ssiforum.com

Introduction

Note: Contact your Intel field sales representative for the latest revision and order number of this docume nt.

1.4 Definition of Terms

Table 1-2. Terms and Descriptions (Sheet 1 of 2)

Term Description

Bypass Bypass is the area between a passive heatsink and any object that can act to form a duct. For this

Digital Thermal Sensor

FMB Flexible Motherboard Guideline: an estimate of the maximum value of a processor specification over

FSC Fan Speed Control IHS Integrated Heat Spreader: a component of the processor package used to enhance the thermal

LGA771 Socket The Dual-Core Intel

MAX

PECI A proprietary one-wire bus interface that provides a communication channel between Intel processor and

CASE

CASE_MAX

TCC Thermal Control Circuit: Thermal monitor uses the TCC to reduce the die temperature by using clock

CONTROL

OFFSET

TDP Thermal Design Power: Ther mal solution should be desi gned to dissipate this target power level. TDP is not

Thermal Monitor A feature on the processor that can keep the processor’s die temperature within factory specifications

Thermal Profile Line that defines case temperature specification of a processor at a given power level. TIM Therma l Inte rface Material: The thermally conductive compound between the heatsink and the processor

example, it can be expressed as a dimension away from the outside dimension of the fins to the nearest surface.

Digital Thermal Sensor replaces the T PROCHOT# sensor to indicate the on-die temperature. The temperature value represents the number of

in previous products and uses the same sensor as the

DIODE

degrees below the TCC activation temperature.

certain time periods. System designers should meet the FMB values to ensure their systems are compatible with future processor releases.

performance of the package. Component thermal solutio ns interface with the processor at the IHS surface.

771 Land socket. See the LGA771 Socket Mechanical Design Guide for details regarding this socket.

Xeon® Processor 5100 Series interface to the baseboard through this surface mount,

The maximum power dissipated by a semiconductor component.

chipset components to external thermal monitoring devices, for use in fan speed control. PECI communicates readings from the processor’s Digital Thermal Sensor. PECI replaces the thermal diode available in previous processors.

Case-to-ambient thermal characterization parameter (psi). A measure of thermal solution performance using total package power. Defined as (T specified for Ψ measurements.

– TLA) / Total Package Power. Heat source should always be

CASE

Case-to-sink thermal characterization parameter. A measure of thermal interface material performance using total package power. Defined as (T

Sink-to-ambient thermal characterization parameter. A measure of heatsink thermal performance using total package power. Defined as (T

– TLA) / Total Package Power.

– TS) / Total Package Power.

CASE

The case temperature of the processor, measured at the geometric center of the topside of the IHS. The maximum case temperature as specified in a component specification.

modulation and/or operating frequency and input voltage adjustment when the die temperature is very near its operating limits.

A processor unique value for us e in fan speed control mechanisms. T based on a temperature reading from the processor’ s Digital Thermal Sensor. T a trigger point for fan speed control implementation. T

An offset value from the TCC activation temperature value specified in the processor EMTS or data sheet and T obtained by reading the IA_32_TEMPERATURE_TARGET MSR. This is a static and a unique value. Refer to

CONTROL

= -T

. This value is programmed into each processor during manufacturing and can be

OFFSET

CONTROL

= -T

OFFSET

is a temperature specification

CONTROL

can be described as

CONTROL

the RS - Conroe and Woodcrest Processor Family BIOS Writer’s Guide (BWG) for further details.

the maximum power that the processor can dissipate.

under normal operating conditions, and with a thermal solution that satis fies the processor thermal profile specification.

case. This material fills the air gaps and voids, and enhances the transfer of the heat from the processor case to the heatsink.

8 Dual-Core Intel® Xeon® Processor 5100 Series Thermal/Mechanical Design Guide

Introduction

Table 1-2. Terms and Descriptions (Sheet 2 of 2)

U A unit of measure used to define server rack spacing heigh t . 1U is equal to 1.75 in, 2U equals 3.50 in, e tc.

The measured ambient temperature locally surrounding the processor. The ambient temperature should be measured just upstream of a passive heatsink or at the fan inlet for an active heatsink.

The system ambient air temperature external to a system chassis. This t emperature is usually measured at the chassis air inlets.

Dual-Core Intel® Xeon® Processor 5100 Series Thermal/Mechanical Design Guide 9

Introduction

10 Dual-Core Intel® Xeon® Processor 5100 Series Thermal/Mechanical Design Guide

Thermal/Mechanical Reference Design

2 Thermal/Mechanical Reference

Design

This chapter describes the thermal/mechanical reference design for Dual-Core Intel Xeon Processor 5100 Series. Dual-Core Intel Xeon Processor 5100 Series are the performance processors with a front side bus speed of 1333 MHz, Some lower speed Dual-Core Intel Xeon Processor 5100 Series SKU’s are available which support a 1066 MHz Front Side Bus (FSB). The processor is targeted for the full range of form factors (2U, 2U+ and 1U/volumetrically constrained).

2.1 Mechanical Requirements

The mechanical performance of the processor cooling solution must satisfy the requirements described in this section.

2.1.1 Processor Mechanical Parameters

Table 2-1. Processor Mechanical Parameters Table

Parameter Minimum Maximum Unit Notes

Volumetric Requirements and Keepouts

Static Compressive Load 3 Static Board Deflection 3 Dynamic Compressive Load 3 Transient Bend 3 Shear Load 70

311

Tensile Load 25

Torsion Load 35

Notes:

1. Refer to drawings in Appendix A.

2. In the case of a discrepancy, the most recent Dual-Core Intel® Xeon® Processor 5100 Series Datasheet and LGA771 Socket Mechanical Design Guide supersede targets listed in Table 2-1 above.

3. These socket limits are defined in the LGA771 Socket Mechanical Design Guide.

4. These package handling limits are defined in the Dual-Core Intel® Xeon® Processor 5100 Series

Datasheet.

5. Shear load that can be applied to the package IHS.

6. Tensile load that can be applied to the package IHS.

7. Torque that can be applied to the package IHS.

111

3.95

lbf

in*lbf

N*m

2,4,5

2,4,6

2,4,7

2.1.2 Dual-Core Intel Xeon Processor 5100 Series Processor Package

The Dual-Core Intel Xeon Processor 5100 Series are packaged using the flip-chip land grid array (FC-LGA6) package technology. Please refer to the Dual-Core Intel

Xeon®

Processor 5100 Series Datasheet for detailed mechanical specifications. The Dual-Core

Intel Xeon Processor 5100 Series mechanical drawing, Figure 2-1, provides the mechanical information for Dual-Core Intel Xeon Processor 5100 Series. The stackup

Dual-Core Intel® Xeon® Processor 5100 Series Thermal/Mechanical Design Guide 11

Thermal/Mechanical Reference Design

height of the processor in the socket is shown in Appendix A. The drawing is superseded with the drawing in the processor Datasheet, should there be any conflicts. Integrated package/socket stackup height information is provided in the LGA771 Socket Mechanical Design Guide.

12 Dual-Core Intel® Xeon® Processor 5100 Series Thermal/Mechanical Design Guide

Thermal/Mechanical Reference Design

Figure 2-1. Dual-Core Intel® Xeon® Processor 5100 Series Mechanical Drawing

Dual-Core Intel® Xeon® Processor 5100 Series Thermal/Mechanical Design Guide 13

Thermal/Mechanical Reference Design

The package includes an integrated heat spreader (IHS). The IHS transfers the nonuniform heat from the die to the top of the IHS, out of which the heat flux is more uniform and spreads over a larger surface area (not the entire IHS area). This allows more efficient heat transfer out of the package to an attached cooling device. The IHS is designed to be the interface for contacting a heatsink. Details can be found in the

Dual-Core Intel

Xeon® Processor 5100 Series Datasheet.

The processor connects to the baseboard through a 771-land surface mount socket. A description of the socket can be found in the LGA771 Socket Mechanical Design Guide.

The processor package and socket have mechanical load limits that are specified in the

Dual-Core Intel

Xeon® Processor 5100 Series Datasheet and the LGA771 Socket

Mechanical Design Guide. These load limits should not be exceeded during heatsink

installation, removal, mechanical stress testing, or standard shipping conditions. For example, when a compressive static load is necessary to ensure thermal performance of the Thermal Interface Material (TIM) between the heatsink base and the IHS, it should not exceed the corresponding specification given in the LGA771 Socket Mechanical Design Guide.

The heatsink mass can also add additional dynamic compressive load to the package during a mechanical shock event. Amplification factors due to the impact force during shock must be taken into account in dynamic load calculations. The total combination of dynamic and static compressive load should not then exceed the processor/socket compressive dynamic load specified in the LGA771 Socket Mechanical Design Guide during a vertical shock. It is not recommended to use any portion of the processor substrate as a mechanical reference or load-bearing surface in either static or dynamic compressive load conditions.

2.1.3 Dual-Core Intel Xeon Processor 5100 Series Considerations

An attachment mechanism must be designed to support the heatsink since there are no features on the LGA771 socket to directly attach a heatsink. In addition to holding the heatsink in place on top of the IHS, this mechanism plays a significant role in the robustness of the system in which it is implemented, in particular:

• Ensuring thermal performance of the TIM applied between the IHS and the heatsink. TIMs, especially ones based on phase change materials, are very sensitive to applied pressure: the higher the pressure, the better the initial performance. TIMs such as thermal greases are not as sensitive to applied pressure. Refer to Section 2.4.2 and Section 2.4.7.2 for information on tradeoffs made with TIM selection. Designs should consider possible decrease in applied pressure over time due to potential structural relaxation in enabled components.

• Ensuring system electrical, thermal, and structural integrity under shock and vibration events. The mechanical requirements of the attach mechanism depend on the weight of the heatsink and the level of shock and vibration that the system must support. The overall structural design of the baseboard and system must be considered when designing the heatsink attach mechanism. Their design should provide a means for protecting LGA771 socket solder joints as well as preventing package pullout from the socket.

Note: The load applied by the attachment mechanism must comply with the package and

socket specifications, along with the dynamic load added by the mechanical shock and vibration requirements, as identified in Section 2.1.1.

14 Dual-Core Intel® Xeon® Processor 5100 Series Thermal/Mechanical Design Guide

Thermal/Mechanical Reference Design

A potential mechanical solution for heavy heatsinks is the direct attachment of the heatsink to the chassis pan. In this case, the strength of the chassis pan can be utilized rather than solely relying on the baseboard strength. In addition to the general guidelines given above, contact with the baseboard surfaces should be minimized during installation in order to avoid any damage to the baseboard.

The Intel reference design for Dual-Core Intel Xeon Processor 5100 Series is using such a heatsink attachment scheme. Refer to Section 2.4 for further information regarding the Intel reference mechanical solution.

2.2 Processor Thermal Parameters and Features

2.2.1 Thermal Control Circuit and TDP

The operating thermal limits of the processor are defined by the Thermal Profile. The intent of the Thermal Profile specification is to support acoustic noise reduction through fan speed control and ensure the long-term reliability of the processor. This specification requires that the temperature at the center of the processor IHS, known as (T T

CASE

(See the Intel Temperature definition and measurement methods).

) remains within a certain temperature specification. Compliance with the

CASE

specification is required to achieve optimal operation and long-term reliability

Xeon® Processor Family Thermal Test Vehicle User's Guide for Case

To ease the burden on thermal solutions, the Thermal Monitor feature and associated logic have been integrated into the silicon of the processor. One feature of the Thermal Monitor is the Thermal Control Circuit (TCC). When active, the TCC lowers the processor temperature by reducing power consumption. This is accomplished through a combination of Thermal Monitor and Thermal Monitor 2(TM2).Thermal Monitor modulates the duty cycle of the internal processor clocks, resulting in a lower effective frequency , wh en active, the T CC turns the processor clocks off and then back on with a predetermined duty cycle. Thermal Monitor 2 adjusts both the processor operating frequency (via the bus multiplier) and input voltage (via the VID signals). Please refer to applicable processor Datasheet for further details on TM and TM2.

PROCHOT# is designed to assert at or a few degrees higher than maximum T

CASE

(as specified by the thermal profile) when dissipating TDP power , and cannot be inter preted as an indication of processor case temperature. This temperature delta accounts for processor package, lifetime, and manufacturing variations and attempts to ensure the Thermal Control Circuit is not activated below maximum T

when dissipating TDP

CASE

power. There is no defined or fixed correlation between the PROCHOT# assertion temperature and the case temperature. However, with the introduction of the Digital Thermal Sensor (DTS) on the Dual-Core Intel

Xeon® Processor 5100 Series, the DTS reports a relative temperature delta below the PROCHOT# assertion temperature (see

Section 2.2.2 for more details on the Digital Thermal Sensor). Thermal solutions must

be designed to the processor specifications (that is, Thermal Profile) and cannot be adjusted based on experimental measurements of T

, PROCHOT#, or Digital

CASE

Thermal Sensor on random processor samples. By taking advantage of the Thermal Monitor features, system designers may reduce

thermal solution cost by designing to the Thermal Design Power (TDP) instead of maximum power. TDP should be used for processor thermal solution design targets. TDP is not the maximum power that the processor can dissipate. TDP is based on measurements of processor power consumption while running various high power applications. This data set is used to determine those applications that are interesting from a power perspective. These applications are then evaluated in a controlled thermal environment to determine their sensitivity to activation of the thermal control

Dual-Core Intel® Xeon® Processor 5100 Series Thermal/Mechanical Design Guide 15

circuit. This data set is then used to derive the TDP targets published in the processor Datasheet. The Thermal Monitor can protect the processor in rare workload excursions above TDP. Therefore, thermal solutions should be designed to dissipate this target power level. The thermal management logic and thermal monitor features are discussed in extensive detail in the Dual-Core Intel

Datasheet.

In addition, on-die thermal management features called THERMTRIP# and FORCEPR# are available on the Dual-Core Intel Xeon Processor 5100 Series. They provide a thermal management approach to support the continued increases in processor frequency and performance. Please see the Dual-Core Intel Series Datasheet for guidance on these thermal management features.

2.2.2 Digital Thermal Sensor

The Dual-Core Intel Xeon Processor 5100 Series introduce a new on-die temperature sensor known as the Digital Thermal Sensor (DTS) that replaces the Tdiode in previous products.

The DTS uses the same sensor utilized for TCC activation. Each individual processor is calibrated so that TCC activation occurs at a DTS value of 0°C. The temperature reported by the DTS is the number of degrees below the TCC activation temperature (i.e below 0°C), and is always negative. For example, -10 reported by DTS means 10°C away from the TCC activ ation. No value above the TCC activation temperature (that is, above 0°C) will be reported, DTS will simply report 0.

Thermal/Mechanical Reference Design

Xeon® Processor 5100 Series

Xeon® Processor 5100

The DTS utilizes a thermal sensor that is optimally located when compared with thermal diodes available with legacy processors. This is achieved as a result of a smaller foot print and decreased sensitivity to noise.

The DTS also facilitates the use of multiple thermal sensors within the processor without the burden of increasing the number of thermal sensor signal pins on the processor package. With the legacy thermal diode, each thermal sensor required dedicated signal pins. Operation of multiple DTS will be discussed more detail in

Section 2.2.4.

The DTS benefits will be realized in more accurate fan speed control and TCC activation. The DTS application in fan speed control will be discussed more detail in

Section 2.3.1.

2.2.3 Platform Environmental Control Interface (PECI)

The PECI interface is designed specifically to convey system management information from the processor (initially , only thermal data fr om the Digital Thermal Sensor). It is a proprietary single wire bus between the processor and the chipset or other health monitoring device. Data from the Digital Thermal Sensors are processed and stored in a processor register (MSR) which is queried through the Platform Environment Control Interface (PECI). The PECI specification provides a specific command set to discover, enumerate devices, and read the temperature. For an overview of the PECI interface, please refer to PECI Feature Set Overview. For more detail information on PECI, please refer to Platform Environment Control Interface (PECI) Specification and Dual-Core

Xeon® Processor 5100 Series Datasheet.

Intel

16 Dual-Core Intel® Xeon® Processor 5100 Series Thermal/Mechanical Design Guide

Thermal/Mechanical Reference Design

2.2.4 Multiple Core Special Considerations

2.2.4.1 Multiple Digital Thermal Sensor Operation

When Intel designers integrate multiple Digital Thermal Sensors onto a processor to monitor multiple temperature regions, such as multiple cores, the only temperature of concern to the external cooling system is the single hottest value for the entire processor.

To simplify the process of determining the hottest location, the PECI interface to the Digital Thermal Sensors introduces the concept of domain. Figure 2-2 provides an illustration of the DTS domain for Dual-Core Intel Xeon Processor 51 00 Series. The Dual-Core Intel Xeon Processor 5100 Series contains two cores, both cores are in one domain with one Digital Thermal Sensor per core. Some multiple core processors have a single domain, other processors will have multiple domains. Each domain receives all temperature sensor values on the processor within that domain, and provides the current hottest value for that domain when polled by an external PECI device such as a thermal management system. The BIOS will be responsible for detecting the proper processor type and providing the number of domains to the thermal management system.

Figure 2-2. DTS Domain for Dual-Core Intel Xeon Processor 5100 Series

Fan Speed Controller

PECI Host

Socket 0

Domain=0

Core_1

DTS_1

Tcontrol for

Tcontrol for Processor 0

Processor 0

2.2.4.2 Thermal Monitor for Multiple Core Products

The thermal management for multiple core products have only one T processor. If the DTS temperature from any domain within the processor is greater than or equal to T temperature as specified by the thermal profile. See Section 2.2.6 for information on T

CONTROL

Core_2

DTS_2

, the processor case temperature must remain at or below the

Core_1

DTS_1

Socket 1

Domain=0

Core_2

DTS_2

Tcontrol for

Processor 1

CONTROL

value per

Dual-Core Intel® Xeon® Processor 5100 Series Thermal/Mechanical Design Guide 17

Thermal/Mechanical Reference Design

2.2.4.3 Fan Speed Control for Dual-Core Intel Xeon Processor 5100 Series

There is only one pin (Pin G5) on each LGA771 socket that accesses the single domain of the Dual-Core Intel Xeon Processor 5100 Series. Through this pin, the single domain receives all temperature sensor values and provides the current hottest value to an external PECI device such as a thermal management system. Figure 2-3 provides an illustration of the fan speed signals for the multiple core Dual-Core Intel Processor 5100 Series.

Figure 2-3. Fan Speed Control for Dual-Core Intel Xeon Processor 5100 Series

Dig ital te mp M S R Core 1

Temperature

FSC

Temperature

Averaging

PECI

LPF

MAX

Core 1

DTS Logic

Xeon®

Temperature

Averaging

Digital temp MSR Core 2

LPF

The processor MSR supports temperature threshold interrupts and provides instantaneous data. To reduce the sample rate requirements on PECI and improve thermal data stability vs. time, the processor Digital Thermal Sensor and PECI interface implement an averaging algorithm. For more information on the Processor Thermal Data Sample Rate and Filtering, please refer to Dual-Core Intel

5100 Series Datasheet.

2.2.4.4 PROCHOT#, THERMTRIP#, and FORCEPR#

The PROCHOT# and THERMTRIP# outp uts will be shared by all cores on a processor. The first core to reach TCC activation will assert PROCHOT#. A single FORCEPR# input will be shared by each core. Table 2-2 provides an overview of input and output conditions for the Dual-Core Intel Xeon Processor 5100 Series thermal management features.

Core 2

DTS Logic

Xeon® Processor

18 Dual-Core Intel® Xeon® Processor 5100 Series Thermal/Mechanical Design Guide

Thermal/Mechanical Reference Design

Table 2-2. Input and Output Conditions for the Dual-Core Intel Xeon Processor 5100

Series Thermal Management Features

Item Processor Input Processor Output

TM/TM2 DTSCore X > TCC Activation Temperature All Cores TCC Activation PROCHOT# DTSCore THERMTRIP# DTSCore

FORCEPR# FORCEPR# Asserted All Cores TCC Activation

Notes:

1. X=1,2, represents any one of the core1and core2 in Dual-Core Intel Xeon Processor 5100 Series.

2. For more information on PROCHOT#, THERMTRIP#, and FORCEPR# see the Dual-Core Intel® Xeon®

Processor 5100 Series Datasheet.

Temperature

X > TCC Activation Temperature PROCHOT# Asserted X > THERMTRIP # Assertion

THERMTRIP# Asserted, all cores shut down

2.2.4.5 Heatpipe Orientation for Multiple Core Processors

Thermal management of multiple core processors can be achieved without the use of heatpipe heatsinks, as demonstrated by the Intel Reference Thermal Solution discussed in Section 2.4.

To assist customers interested in designing heatpipe heatsinks, processor core locations have been provided. In some cases, this may influence the designer’s selection of heatpipe orientation. For this purpose, the core geometric center locations, as illustrated in Figure 2-4, are provided in Table 2-3. Dimensions originate from the vertical edge of the IHS nearest to the pin 1 fiducial as shown in Figure 2-4.

Dual-Core Intel® Xeon® Processor 5100 Series Thermal/Mechanical Design Guide 19

Figure 2-4. Processor Core Geometric Center Locations

Thermal/Mechanical Reference Design

Table 2-3. Processor Core Geometric Center Dimensions

Feature X Dimension Y Dimension

Core 1 19.53 mm 12.68 mm Core 2 19.53 mm 16.82 mm

2.2.5 Thermal Profile

The thermal profile is a linear line that defines the relationship between a processor’s case temperature and its power consumption as shown in Figure 2-5. The equation of the thermal profile is defined as:

Equation 2-1.y = ax + b

Where:

y =Processor case temperature, T

20 Dual-Core Intel® Xeon® Processor 5100 Series Thermal/Mechanical Design Guide

CASE

(°C)

Thermal/Mechanical Reference Design

x =Processor power consumption (W) a =Case-to-ambient thermal resistance, ψCA (°C/W) b =Processor local ambient temperature, TLA (°C)

Figure 2-5. Thermal Profile Diagram

MAX

CASE

MAX@

CASE

_PROFILE_MIN

CASE

Thermal Profile

TDP

_PROFILE_MIN

Power

TDP

The higher end point of the Thermal Profile represents the processor’s TDP and the associated maximum case temperature (T

CASE_MAX

Thermal Profile represents the power value (P temperature (T T

CONTROL

(see Section 2.2.6). The slope of the Thermal Profile line represents the case-

CASE_MAX

@ P

_PROFILE_MIN

) for the lowest possible theoretical value of

). The lower end point of the

_PROFILE_MIN

) and the associated case

to-ambient resistance of the thermal solution with the y-intercept being the local processor ambient temperature. The slope of the Thermal Profile is constant between P

_PROFILE_MIN

and TDP, which indicates that all frequencies of a processor defined by

the Thermal Profile will require the same heatsink case-to-ambient resistance. In order to satisfy the Thermal Profile specification, a thermal solution must be at or

below the Thermal Profile line for the given processor when its DTS temperature is greater than T

CONTROL

(refer to Section 2.2.6). The Thermal Profile allows the customers to make a trade-off between the thermal solution case-to-ambient resistance and the processor local ambient temperature that best suits their platform implementation (refer to Section 2.3.3). There can be multiple combinations of thermal solution case-to-ambient resistance and processor local ambient temperature that can meet a given Thermal Profile. If the case-to-ambient resistance and the local ambient temperature are known for a specific thermal solution, the Thermal Profile of that solution can easily be plotted against the Thermal Profile specification. As explained above, the case-to-ambient resistance represents the slope of the line and the processor local ambient temperature represents the y-axis intercept. Hence the T values of a specific solution can be calculated at the TDP and P

_PROFILE_MIN

power

CASE

levels. Once these points are determined, they can be joined by a line, which represents the Thermal Profile of the specific solution. If that line stays at or below the Thermal Profile specification, then that particular solution is deemed as a compliant solution.

Dual-Core Intel® Xeon® Processor 5100 Series Thermal/Mechanical Design Guide 21

Thermal/Mechanical Reference Design

2.2.6 T

T processor T the Digital Thermal Sensor are relative and no longer absolute, the T now defined as a relative value to the TCC activation set point (that is, 0°C). Figure 2-6 depicts the interaction between the T

Figure 2-6. T

CONTROL

Digital Thermal Sen sorTemperature

Tcontrol = -5

Definition

can be described as a trigger point for fan speed control implementation. The

CONTROL

Value and Digital Thermal Sensor Value Interaction

value is now a DTS value. Because the temperatures provided by

CONTROL

-10

-20

-30

-40

CONTROL

value and Digital Thermal Sensor value.

Temperature

valu e is

The value for T individually. For the Dual-Core Intel Xeon Processor 5100 Series, the T obtained by reading a processor model specific register (MSR). NOTE: There is no T control device only needs to read the T from the PECI interface. The equation for calculating T

Equation 2-2.T

Where:

Figure 2-7 depicts the interaction between the Thermal Profile and T

Time

CONTROL

CONTROL_BASE

CONTROL

OFFSET

manufacturing that can be obtained by reading the IA32_TEMPERATURE_TARGET MSR. This is a static and a unique value. Refer to the RS - Conroe and Woodcrest Processor Family BIOS Writer’s Guide for further details.

value to sum as previously required on legacy processors. The fan speed

= -T

OFFSET

= A DTS-based value programmed into each processor during

is calibrated in manufacturing and configured for each processor

CONTROL

MSR and compare this to the DTS value

OFFSET

CONTROL

is:

CONTROL

value is

22 Dual-Core Intel® Xeon® Processor 5100 Series Thermal/Mechanical Design Guide

Thermal/Mechanical Reference Design

Figure 2-7. T

CONTROL

CASE

@DT S=

CASE

CONTROL

MAX@

CASE

_PROFILE_MIN

and Thermal Profile Interaction

MAX

②

①

CASE

_PROFILE_MIN

Power

Thermal Profile

TDP

Since T

CONTROL

temperature must be determined to plot the T Profile graph. Location 1 on the Thermal Profile represents a T to P

_PROFILE_MIN

corresponding to DTS = T

is based on a processor DTS temperature value, an equivalent T

@ T

CASE

CONTROL

. Location 2 on the Thermal Profile represents a T

CONTROL

. If the DTS temperature is less than T

point on the Thermal

value corresponding

CASE

valu e

CONTROL

the case temperature is permitted to exceed the Thermal Profile, but the DTS temperature must remain at or below T must be able to keep the processor’s T Thermal Profile between the T

CASE_MAX

CONTROL

CASE

. The thermal solution for the processor

at or below the T

_PROFILE_MIN

and T

values defined by the

CASE

CASE_MAX

points at the

corresponding power levels. Refer to Section 2.3.1 for the implementation of the T

CONTROL

value in support of fan

speed control (FSC) design to achieve better acoustic performance.

2.2.7 Thermal Profile Concepts for the Dual-Core Intel Xeon Processor 5100 Series

2.2.7.1 Dual Thermal Profile Concept for the Dual-Core Intel Xeon

Processor 5160

The Dual-Core Intel Xeon Processor 5160 are designed to go into various form factors, including the volumetrically constrained 1U and custom blade form factors. Due to certain limitations of such form factors (that is, airflow, thermal solution height), it is very challenging to meet the thermal requirements of the processor. To mitigate these form factor constraints, Intel has developed a dual Thermal Profile specification, shown in Figure 2-8.

CASE

, then

Dual-Core Intel® Xeon® Processor 5100 Series Thermal/Mechanical Design Guide 23

Figure 2-8. Dual Thermal Profile Diagram

MAX B

CASE

MAX A

CASE

MAX@

CASE

_PROFILE_MIN

CASE

Thermal Profile B

Thermal/Mechanical Reference Design

Thermal P r o file A

_PROFILE_MIN_B

_PROFILE_MIN_A

Power

TDP

The Thermal Profile A is based on Intel’s 2U+ air cooling solution. Designing to Thermal Profile A ensures that no measurable performance loss due to Thermal Control Circuit (TCC) activation is observed in the processor. It is expected that TCC would only be activated for very brief periods of time when running a worst-case real world application in a worst-case thermal condition. These brief instances of TCC activation are not expected to impact the performance of the processor. A worst case real world application is defined as a commercially available, useful application which dissipates a power equal to, or above, the TDP for a thermally relevant timeframe. One example of a worst-case thermal condition is when a processor local ambient temperature is at or above 42.3°C for Dual-Core Intel Xeon Processor 5160 Thermal Profile A.

Thermal Profile B supports volumetrically constrained platforms (that is, 1U, blades, and so forth), and is based on Intel’s 1U air cooling solution. Because of the reduced capability represented by such thermal solutions, designing to Thermal Profile B results in an increased probability of TCC activation and an associated measurable performance loss. Measurable performance loss is defined to be any degradation in the processor’s performance greater than 1.5%. The 1.5% number is chosen as the baseline since the run-to-run variation in a given performance benchmark is typically between 1 - 2%.

Although designing to Thermal Profile B results in increased T

temperatures

CASE

compared to Thermal Profile A at a given power level, both of these Thermal Profiles ensure that Intel’s long-term processor reliability requirements are satisfied. In other words, designing to Thermal Profile B does not impose any additional risk to Intel’s long-term reliability requirements. Thermal solutions that exceed Thermal Profile B specification are considered incompliant and will adversely affect the long-term reliability of the processor.

24 Dual-Core Intel® Xeon® Processor 5100 Series Thermal/Mechanical Design Guide

Thermal/Mechanical Reference Design

Refer to the Dual-Core Intel® Xeon® Processor 5100 Series Datasheet or Section 2.2.8 for the Thermal Profile A and Thermal Profile B specifications. Section 2.4 of this document also provides details on the 2U+ and 1U Intel reference thermal solutions that are designed to meet the Dual-Core Intel Xeon Processor 5160 and Thermal Profile B respectively.

2.2.8 Performance Targets

The Thermal Profile specifications for these processors are published in the Dual-Core Intel® Xeon® Processor 5100 Series Datasheet. These Thermal Profile specifications

are shown as a reference in the subsequent discussions.

Figure 2-9. Thermal Profile for the Dual-Core Intel Xeon Processor 5148

TCASE_MAX@TDP

Y = 0.450*x +40.0

Thermal Profile A

Temperature [C]

20 22 24 26 28 30 32 34 36 38 40

Note: The thermal specifications shown in this graph are for reference only. Refer to the

Dual-Core Intel

Xeon® Processor 5100 Series Datasheet for the Thermal Profile

Power [W]

specifications. In case of conflict, the data information in the datasheet supersedes any data in this figure.

Dual-Core Intel® Xeon® Processor 5100 Series Thermal/Mechanical Design Guide 25

Thermal/Mechanical Reference Design

Figure 2-10. Thermal Profile for the Dual-Core Intel® Xeon® Processor 5110/5120/5130/

5140/5150

TCASE_MAX@TDP

Temperature [C]

20 25 30 35 40 45 50 55 60 65

TCASE_MAX@TDP

Power [W]

Y = 0.385*x +40.0

Note: The thermal specifications shown in this graph are for reference only. Refer to the

Dual-Core Intel

Xeon® Processor 5100 Series Datasheet for the Thermal Profile

specifications. In case of conflict, the data information in the datasheet supersedes any data in this figure.

26 Dual-Core Intel® Xeon® Processor 5100 Series Thermal/Mechanical Design Guide

Thermal/Mechanical Reference Design

Figure 2-11. Thermal Profiles A and B for the Dual-Core Intel® Xeon® Processor 5160

TCASE_MAX_B@TDP is a thermal solution design point. In actuality, units will

TCASE_MAX_B@TDP is a thermal solution design point. In actuality, units will not significantly exceed TCASE_MAX_A due to TCC activation.

not significantly exceed TCASE_MAX_A due to TCC activation.

TCASE_MAX_B@TDP

Temperature [C]

TCASE_MAX_B@TDP

TCASE_MAX_A@TDP

Thermal Profile B

Thermal Profile B Y = 0.282*x +42.4

Y = 0.282*x +42.4

Thermal Profile A

Thermal Profile A Y = 0.231*x +41.5

Y = 0.231*x +41.5

10 15 20 25 30 35 40 45 50 55 60 65 70 75 80

Power [W]

Note: The thermal specifications shown in this graph are for reference only. Refer to the Dual-

Core Intel

Xeon® Processor 5100 Series Datasheet for the Thermal Profile

specifications. In case of conflict, the data information in the datasheet supersedes any data in this figure.

Table 2-4, Table 2-5 and Table 2-6 describe thermal performance target for the Dual-

Core Intel Xeon Processor 5100 Series cooling solution enabled by Intel.

Table 2-4. Intel Reference Heatsink Performance Targets for the Dual-Core Intel®

Xeon® Processor 5148

Parameter Maximum Unit Notes

Altitude Sea-level m Heatsink designed at 0 meters

TDP 40 W

CASE_MAX

@ P_profile_min 50 ° C P_profile_min = 22.2 W.

Airflow 15

Pressure Drop 0.331

40 ° C

58 ° C

CFM

25.5

82.4

0.299 ° C/W Mean + 3σ

/ hr

Inches of H

Airflow through the heatsink fins

Dual-Core Intel® Xeon® Processor 5100 Series Thermal/Mechanical Design Guide 27

Thermal/Mechanical Reference Design

Table 2-5. Intel Reference Heatsink Performance Targets for the Dual-Core Intel Xeon

Processor 5110/5120/5130/5140/5150

Parameter Maximum Unit Notes

Altitude Sea-level m Heatsink designed at 0 meters

TDP 65 W

CASE_MAX

@ P_profile_min 50 ° C P_profile_min= 26 W.

Airflow 15

Pressure Drop 0.331

40 ° C

65 ° C

25.5

82.4

CFM

/ hr

Inches of H

Airflow through the heatsink fins

0.299 ° C/W Mean + 3σ

28 Dual-Core Intel® Xeon® Processor 5100 Series Thermal/Mechanical Design Guide

Thermal/Mechanical Reference Design

Table 2-6. Intel Reference Heatsink Performance Targets for the Dual-Core Intel Xeon

Processor 5160

Parameter Maximum Unit Notes

Altitude Sea-level m Heatsink designed at 0 meters

TDP 80 W

CASE_MAX_A

CASE_MAX

@ P_profile_min 50 ° C P_profile_min= 36.8 W.

Airflow 27

Pressure Drop 0.182

CASE_MAX_B

(Profile B)

@ P_profile_min

(Profile B)

Airflow 15

Pressure Drop 0.331

40 ° C

2U+ Reference Solution, Thermal Profile A

60 ° C

CFM

45.9

45.3

0.236 ° C/W Mean + 3σ

1U Reference Solution, Thermal Profile B

65 ° C

50 ° C P_profile_min = 27 W.

25.5

82.4

0.299 ° C/W Mean + 3σ

/ hr

Inches of H

CFM

/ hr

Inches of H

Airflow through the heatsink fins

Note: In case of conflict, the processor datasheet supersedes the information contained in the TMDG.

2.3 Characterizing Cooling Solution Performance Requirements

2.3.1 Fan Speed Control

Fan speed control (FSC) techniques to reduce system level acoustic noise are a common practice in server designs. The fan speed is one of the parameters that determine the amount of airflow provided to the thermal solution. Additionally, airflow is proportional to a thermal solution’s performance, which consequently determines the

of the processor at a given power level. Since the T

CASE

important parameter in the long-term reliability of a processor, the FSC implemented in a system directly correlates to the processor’s ability to meet the Thermal Profile and hence the long-term reliability requirements. For this purpose, the parameter called T

CONTROL

as explained in Section 2.2.6, is to be used in FSC designs to ensure that the long-term reliability of the processor is met while keeping the system level acoustic noise down. Figure 2-12

depicts the relationship between T

methodology.

of a processor is an

CASE

CONTROL

and FSC

Dual-Core Intel® Xeon® Processor 5100 Series Thermal/Mechanical Design Guide 29

Thermal/Mechanical Reference Design

Figure 2-12. T

CONTROL

Fan Speed Control Region

and Fan Speed Control

MAX

CASE

@DTS =

CASE

CONTROL

MAX@

CASE

_PROFILE_MIN

Thermal Profile

②

①

CASE

_PROFILE_MIN

Power

Thermal Profile

TDP

Once the T

CONTROL

value is determined as explained earlier, the DTS temperature reading from the processor can be compared to this T control scheme can be implemented as described in Table 2-7 without compromising the long-term reliability of the processor.

Table 2-7. Fan Speed Control, T

Condition FSC Scheme

DTS≤ T

CONTROL

DTS>T

CONTROL

There are many different ways of implementing fan speed control, including FSC based on processor ambient temperature, FSC based on processor Digital Thermal Sensor (DTS) temperature or a combination of the two. If FSC is based only on the processor ambient temperature, low acoustic targets can be achieved under low ambient temperature conditions. However, the acoustics cannot be optimized based on the behavior of the processor temperature. If FSC is based only on the Digital Thermal Sensor, sustained temperatures above T based both on ambient and Digital Thermal Sensor, ambient temperature can be used to scale the fan RPM controlled by the Digital Thermal Sensor. This would result in an optimal acoustic performance. Regardless of which scheme is employed, system designers must ensure that the Thermal Profile specification is met when the processor Digital Thermal Sensor temperature exceeds the T

CONTROL

FSC can adjust fan speed to maintain DTS = T

FSC should adjust fan speed to keep T specification (increased acoustic region).

and DTS Relationship

CASE

CONTROL

drives fans to maximum RPM. If FSC is

CONTOL

at or below the Thermal Profile

value. A fan speed

(low acoustic region).

CONTROL

value for a given processor.

30 Dual-Core Intel® Xeon® Processor 5100 Series Thermal/Mechanical Design Guide

Thermal/Mechanical Reference Design

2.3.2 Processor Thermal Characterization Parameter Relationships

The idea of a “thermal characterization parameter”, Ψ (psi), is a convenient way to characterize the performance needed for the thermal solution and to compare thermal solutions in identical conditions (heating source, local ambient conditions). A thermal characterization parameter is convenient in that it is calculated using total package power, whereas actual thermal resistance, θ (theta), is calculated using actual power dissipated between two points. Measuring actual power dissipated into the heatsink is difficult, since some of the power is dissipated via heat transfer into the socket and board. Be aware, however, of the limitations of lumped parameters such as Ψ when it comes to a real design. Heat transfer is a three-dimensional phenomenon that can rarely be accurately and easily modeled by lump values.

The case-to-local ambient thermal characterization parameter value (Ψ measure of the thermal performance of the overall thermal solution that is attached to the processor package. It is defined by the following equation, and measured in units of °C/W:

Equation 2-3.Ψ

Where:

The case-to-local ambient thermal characterization parameter of the processor, Ψ comprised of Ψ local ambient thermal characterization parameter:

Equation 2-4.Ψ

Where:

between the heatsink and IHS.

) is used as a

= (T

CASE

- TLA) /

TDP

=Case-to-local ambient thermal characterization parameter (°C/W). =Processor case temperature (°C). =Local ambient temperature in chassis at processor (°C).

TDP =TDP dissipation (W) (assumes all power dissipates through the integrated

heat spreader (IHS)).

, the TIM thermal characterization parameter, and of ΨSA, the sink-to-

= ΨCS + ΨSA

=Thermal characterization parameter of the TIM (°C/W).

=Thermal characterization parameter from heatsink-to-local ambient (°C/W).

is strongly dependent on the thermal conductivity and thickness of the TIM

, is

is a measure of the thermal characterization parameter from the bottom of the

heatsink to the local ambient air. Ψ

is dependent on the heatsink material, thermal

conductivity, and geometry. It is also strongly dependent on the air velocity through the fins of the heatsink.

Dual-Core Intel® Xeon® Processor 5100 Series Thermal/Mechanical Design Guide 31

Thermal/Mechanical Reference Design

Figure 2-13 illustrates the combination of the different thermal characterization

parameters.

Figure 2-13. Processor Thermal Characterization Parameter Relationships

TLAT

HEATSINK

CASE

TIM

PROCESSOR

IHS

SOCKET

2.3.2.1 Example

The cooling performance, Ψ characterization parameter described above:

• Define a target case temperature T processor EMTS.

• Define a target local ambient temperature at the processor, TLA.

The following provides an illustration of how one might determine the appropriate performance targets. The example power and temperature numbers used here are not related to any Intel processor thermal specifications, and are for illustrative purposes only.

Assume the datasheet TDP is 85 W and the case temperature specification is 68°C. Assume as well that the system airflow has been designed such that the local processor ambient temperature is 45°C. Then the following could be calculated using equation (2-3) from above:

Equation 2-5.Ψ

Equation 2-6.Ψ

= (T

To determine the required heatsink performance, a heatsink solution provider would need to determine Ψ configuration. If the heatsink solution was designed to work with a TIM material performing at Ψ of the heatsink would be:

= ΨCA − ΨCS = 0.27 − 0.05 = 0.22°C/W

If the local processor ambient temperature is assumed to be 40°C, the same calculation can be carried out to determine the new case-to-ambient thermal resistance:

is then defined using the principle of thermal

CA,

CASE_MAX

– TLA) / TDP = (68 – 45) / 85 = 0.27°C/W

CASE

performance for the selected TIM and mechanical load

≤ 0.05°C/W, solving for equation (2-4) from above, the performance

and corresponding TDP, given in the

32 Dual-Core Intel® Xeon® Processor 5100 Series Thermal/Mechanical Design Guide

Thermal/Mechanical Reference Design

Equation 2-7.ΨCA = (T

It is evident from the above calculations that, a reduction in the local processor ambient temperature has a significant positive effect on the case-to-ambient thermal resistance requirement.

– TLA) / TDP = (68 – 40) / 85 = 0.33 °C/W

CASE

2.3.3 Chassis Thermal Design Considerations

2.3.3.1 Chassis Thermal Design Capabilities and Improvements

One of the critical parameters in thermal design is the local ambient temperature assumption of the processor. Keeping the external chassis temperature fixed, internal chassis temperature rise is the only component that can affect the processor local ambient temperature. Every degree gained at the local ambient temperature directly translates into a degree relief in the processor case temperature.

Given the thermal targets for the processor, it is extremely important to optimize the chassis design to minimize the air temperature rise upstream to the processor (T hence minimizing the processor local ambient temperature. Please refer to T Reduction Guidelines for Rack Servers and Workstations for more details.

The heat generated by components within the chassis must be removed to provide an adequate operating environment for both the processor and other system components. Moving air through the chassis brings in air from the external ambient environment and transports the heat generated by the processor and other system components out of the system. The number, size and relative position of fans, vents and other heat generating components determine the chassis thermal performance, and the resulting ambient temperature around the processor. The size and type (passive or active) of the thermal solution and the amount of system airflow can be traded off against each other to meet specific system design constraints. Additional constraints are board layout, spacing, component placement, and structural considerations that limit the thermal solution size.

RISE

rise

In addition to passive heatsinks, fan heatsinks and system fans, other solutions exist for cooling integrated circuit devices. For example, ducted blowers, heat pipes and liquid cooling are all capable of dissipating additional heat. Due to their varying attributes, each of these solutions may be appropriate for a particular system implementation.

To develop a reliable, cost-effective thermal solution, thermal characterization and simulation should be carried out at the entire system level, accounting for the thermal requirements of each component. In addition, acoustic noise constraints may limit the size, number, placement, and types of fans that can be used in a particular design.

2.4 Thermal/Mechanical Reference Design Considerations

2.4.1 Heatsink Solutions

2.4.1.1 Heatsink Design Considerations

To remove the heat from the processor, three basic parameters should be considered:

• The area of the surface on which the heat transfer takes place - Without any enhancements, this is the surface of the proce ssor pack age IHS. One method us ed to improve thermal performance is by attaching a heatsink to the IHS. A heatsink

Dual-Core Intel® Xeon® Processor 5100 Series Thermal/Mechanical Design Guide 33

Thermal/Mechanical Reference Design

can increase the effective heat transfer surface area by conducting heat out of the IHS and into the surrounding air through fins attached to the heatsink base.

• The conduction path from the heat so urce to the heatsink fins - Providing a direct conduction path from the heat source to the heatsink fins and selecting materials with higher thermal conductivity typically improves heatsink performance. The length, thickness, and conductivity of the conduction path from the heat source to the fins directly impact the thermal performance of the heatsink. In particular, the quality of the contact between the package IHS and the heatsink base has a higher impact on the overall thermal solution performance as processor cooling requirements become strict. Thermal interface material (TIM) is used to fill in the gap between the IHS and the bottom surface of the heatsink, and thereby improves the over all performance of the thermal stackup (IHS- TIM-Heatsink). With extremely poor heatsink interface flatness or roughness, TIM may not adequately fill the gap. The TIM thermal performance depends on its thermal conductivity as well as the pressure load applied to it. Refer to Section 2.4.2 for further information on the TIM between the IHS and the heatsink base.

• The heat transfer conditions on the surface on which heat transfer takes place - Convective heat transfer occurs between the airflow and the surface exposed to the flow. It is characterized by the local ambient temperature of the air,

, and the local air velocity over the surface. The higher the air velocity over the

surface, the resulting cooling is more efficient. The nature of the airflow can also enhance heat transfer via convection. Turbulent flow can provide improvement over laminar flow. In the case of a heatsink, the surface exposed to the flow includes the fin faces and the heatsink base.

An active heatsink typically incorporates a fan that helps manage the airflow through the heatsink.

Passive heatsink solutions require in-depth knowledge of the airflow in the chassis. Typically, passive heatsinks see slower air speed. Therefore, these heatsinks are typically larger (and heavier) than active heatsinks due to the increase in fin surface required to meet a required performance. As the heatsink fin density (the number of fins in a given cross-section) increases, the resistance to the airflow increases: it is more likely that the air will travel around the heatsink instead of through it, unless air bypass is carefully managed. Using air-ducting techniques to manage bypass area is an effective method for maximizing airflow through the heatsink fins.

2.4.2 Thermal Interface Material

TIM application between the processor IHS and the heatsink base is generally required to improve thermal conduction from the IHS to the heatsink. Many thermal interface materials can be pre-applied to the heatsink base prior to shipment from the heatsink supplier and allow direct heatsink attach, without the need for a separate TIM dispense or attach process in the final assembly factory.

All thermal interface materials should be sized and positioned on the heatsink base in a way that ensures the entire processor IHS area is covered. It is important to compensate for heatsink-to-processor attach positional alignment when selecting the proper TIM size.

When pre-applied material is used, it is recommended to have a protective application tape over it. This tape must be removed prior to heatsink installation.

34 Dual-Core Intel® Xeon® Processor 5100 Series Thermal/Mechanical Design Guide

Thermal/Mechanical Reference Design

The TIM performance is susceptible to degradation (i.e. grease breakdown) during the useful life of the processor due to the temperature cycling phenomena. F or this reason, the measured T the type of TIM material.

Refer to Section 2.4.7.2 for information on the TIM used in the Intel reference heatsink solution.

CASE

2.4.3 Summary

In summary, considerations in heatsink design include:

• The local ambient temperature TLA at the heatsink, airflow (CFM), the power being dissipated by the processor, and the corresponding maximum T parameters are usually combined in a single lump cooling performance parameter,

(case to air thermal characterization parameter). More information on the

definition and the use of ΨCA is given in Section 2.4 and Section 2.3.2.

• Heatsink interface (to IHS) surface characteristics, including flatness and roughness.

• The performance of the TIM used between the heatsink and the IHS.

• Surface area of the heatsink.

• Heatsink material and technology.

• Development of airflow entering and within the heatsink area.

• Physical volumetric constraints placed by the system.

• Integrated package/socket stackup height information is provided in the LGA771 Socket Mechanical Design Guide.

value of a given processor can decrease over time depending on

. These

CASE

2.4.4 Assembly Overview of the Intel Reference Thermal Mechanical Design

The reference design heatsinks that meet the Dual-Core Intel Xeon Processor 5100 Series processors thermal performance targets are called the Common Enabling Kit (CEK) heatsinks, and are available in 1U, 2U, & 2U+ form factors. Each CEK consists of the following components:

• Heatsink (with captive standoff and screws)

• Thermal Interface Material (TIM)

•CEK Spring

2.4.4.1 Geometric Envelope

The baseboard keepout zones on the primary and secondary sides and height restrictions under the enabling component region are shown in detail i n Appendix A. The overall volumetric keep in zone encapsulates the processor, socket, and the entire thermal/mechanical enabling solution.

Dual-Core Intel® Xeon® Processor 5100 Series Thermal/Mechanical Design Guide 35

Thermal/Mechanical Reference Design

2.4.4.2 Assembly Drawing

Figure 2-14. Exploded View of CEK Thermal Solution Components

The CEK reference thermal solution is designed to extend air-cooling capability through the use of larger heatsinks with minimal airflow blockage and bypass. CEK retention solution can allow the use of much heavier heatsink masses compared to the legacy limits by using a load path directly attached to the chassis pan. The CEK spring on the secondary side of the baseboard provides the necessary compressive load for the thermal interface material. The baseboard is intended to be isolated such that the dynamic loads from the heatsink are transferred to the chassis pan via the stiff screws and standoffs. This reduces the risk of package pullout and solder-joint failures.

The baseboard mounting holes for the CEK solution are at the same location as the hole locations used for previous Intel

Xeon® processor thermal solution. However, CEK assembly requires 10.16 mm [0.400 in.] large diameter holes to compensate for the CEK spring embosses.

The CEK solution is designed and optimized for a baseboard thickness range of 1.57 –

2.31 mm [0.062-0.093 in]. While the same CEK spring can be used for this board thickness range, the heatsink standoff height is different for a 1.57 mm [0.062 in] thick board than it is for a 2.31 mm [0.093 in] thick board. In the heatsink assembly, the standoff protrusion from the base of the heatsink needs to be 0.6 mm [0.024 in] longer for a 2.31 mm [0.093 in] thick board, compared to a 1.57 mm [0.062 in] thick board.

36 Dual-Core Intel® Xeon® Processor 5100 Series Thermal/Mechanical Design Guide

Thermal/Mechanical Reference Design

If this solution is intended to be used on baseboards that fall outside of this range, then some aspects of the design, including but not limited to the CEK spring design and the standoff heights, may need to change. Therefore, system designers need to evaluate the thermal performance and mechanical behavior of the CEK design on baseboards with different thicknesses.

Refer to Appendix A for drawings of the heatsinks and CEK spring. The screws and standoffs are standard components that are made captive to the heatsink for ease of handling and assembly.

Contact your Intel field sales representative for an electronic version of mechanical and thermal models of the CEK (Pro/Engineer*, IGES and Icepak*, Flotherm* formats). Pro/Engineer*, Icepak* and Flotherm* models are available on Intel Business Link (IBL).

Note: Intel reserves the right to make changes and modifications to the design as necessary. Note: The thermal mechanical reference design for the Dual-Core Intel Xeon Processor 5100

Series was verified according to the Intel validation criteria given in Appendix D.1. Any thermal mechanical design using some of the reference components in combination with any other thermal mechanical solution needs to be fully validated according to the customer criteria. Also, if customer thermal mechanical validation criteria differ from the Intel criteria, the reference solution should be validated against the customer criteria.

2.4.4.3 Structural Considerations of CEK

As Intel explores methods of keeping thermal solutions within the air-cooling space, the mass of the thermal solutions is increasing. Due to the flexible nature (and associated large deformation) of baseboard-only attachments, Intel reference solutions, such as CEK, are now commonly using direct chassis attach (DCA) as the mechanical retention design. The mass of the new thermal solutions is large enough to require consideration for structural support and stiffening on the chassis. Intel has published a best know method (BKM) document that provides specific structural guidance for designing DCA thermal solutions. The document is titled Chassis Strength and Stiffness Measurement and Improvement Guidelines for Direct Chassis Attach Solutions.

2.4.5 Thermal Solution Performance Characteristics

Figure 2-15 and Figure 2-16 show the performance of the 2U+ and 1U passive

heatsinks, respectively. These figures show the thermal performance and the pressure drop through fins of the heatsink versus the airflow provided. The best-fit equations for these curves are also provided to make it easier for users to determine the desired value without any error associated with reading the graph.

Dual-Core Intel® Xeon® Processor 5100 Series Thermal/Mechanical Design Guide 37

Figure 2-15. 2U+ CEK Heatsink Thermal Performance

0.45

0.40

P = 3.75e-05CFM

0.35

0.30

0.25

, C/W

0.20

0.15

0.10

0.05

0 102030405060708090100

+ 5.71e-03CFM

Mean

= 0.0024 C/W

CFM Through Fins

Thermal/Mechanical Reference Design

= 0.1811 + 1.2872*CFM

-0.9998

0.80

0.70

0.60

0.50

0.40

0.30

0.20

0.10

0.00

P, inch water

If other custom heatsinks are intended for use with the Dual-Core Intel® Xeon® Processor 5100 Series, they must support the following interface control requirements to be compatible with the reference mechanical components:

• Requirement 1: Heatsink assembly must stay within the volumetric keep-in.

• Requirement 2: Maximum mass and center of gravity.

Current maximum heatsink mass is 1000 grams [2.2 lbs] and the maximum center of gravity 3.81 cm [1.5 in.] above the bottom of the heatsink base.

• Requirement 3: Maximum and minimum compressive load.

Any custom thermal solution design must meet the loading specification as documented within this document, and should refer to the Dual-Core Intel

Xeon®

Processor 5100 Series Datasheet and LGA771 Socket Mechanical Design Guide and for

specific details on package/socket loading specifications.

38 Dual-Core Intel® Xeon® Processor 5100 Series Thermal/Mechanical Design Guide

Thermal/Mechanical Reference Design

Figure 2-16. 1U CEK Heatsink Thermal Performance

0.50

0.45

0.40

0.35

0.30

, C/W

0.25

0.20

Mean

0.15

0.10

0.10 0 1020304050

0 1020304050

Mean

= 0.0028 C/W

CFM Through Fins

2.4.6 Thermal Profile Adherence

The 1U CEK Intel reference thermal solution is designed to meet the Thermal Profile for the Dual-Core Intel® Xeon® Processor 5148. From Table 2-4 the three-sigma (mean+3sigma) performance of the thermal solution is computed to be 0.299°C/W and the processor local ambient temperature (T the Thermal Profile equation for this thermal solution is calculated as:

P = 2.73e-04CFM

= 0.1831 + 1.1113*CFM

) for this thermal solution is 40°C. Hence,

+ 1.86e-02CFM

-0.8634

0.80

0.70

0.60

0.50

0.40

0.30

0.20

0.10

0.00

P, inch water

Equation 2-8.y = 0.299x + 40

where,

y = Processor T

value (°C)

CASE

x = Processor power value (W)

Table 2-17 below shows the comparison of this reference thermal solution’s Thermal

Profile to the Dual-Core Intel

Xeon® Processor 5148 Thermal Profile specification. The 1U CEK solution meets the Thermal Profile with 3.4°C margin at the lower end (P

_PROFILE_MIN

) and 6.0°C margin at the upper end (TDP). By designing to Thermal Profile, it is ensured that no measurable performance loss due to TCC activation is observed under the given environmental conditions.

Dual-Core Intel® Xeon® Processor 5100 Series Thermal/Mechanical Design Guide 39

Thermal/Mechanical Reference Design

Figure 2-17. 1U CEK Thermal Adherence to Dual-Core Intel Xeon Processor 5148 Thermal

Profile

CASE MAX

TDP

CASE_MAX

_PROFILE_MIN

Thermal Profile

50 45

45 40

40 35

35 30

30 25

25 20

20 15

15 10

Tcase [°C]

5 0

0 5 10 15 20 25 30 35 40 45

Thermal Profile

y = 0.450 * x + 40

1U CEK Reference Solution

y = 0.299 * x + 40

PROFILE_MIN

Power [W]

TDP

The 1U CEK Intel reference thermal solution is designed to meet the Thermal Profile for the Dual-Core Intel Xeon Processor 5110/5120/5130/5140/5150. From Table 2-5 the three-sigma (mean+3sigma) performance of the thermal solution is computed to be

0.299 °C/W and the processor local ambient temperature (T is 40 °C. Hence, the Thermal Profile equation for this thermal solution is calculated as:

Equation 2-9.y = 0.299x + 40

where,

y = Processor T x = Processor power value (W)

Figure 2-18 below shows the comparison of this reference thermal solution’s Thermal

Profile to the Dual-Core Intel Xeon Processor 5110/5120/5130/5140/5150 Thermal Profile specification. The 1U CEK solution meets the Thermal Profile with 2.2°C margin at the lower end (P designing to Thermal Profile, it is ensured that no measurable performance loss due to TCC activation is observed under the given environmental conditions.

value (°C)

CASE

_PROFILE_MIN

) for this thermal solution

) and 5.6°C margin at the upper end (TDP). By

40 Dual-Core Intel® Xeon® Processor 5100 Series Thermal/Mechanical Design Guide

Thermal/Mechanical Reference Design

Figure 2-18. 1U CEK Thermal Adherence to Dual-Core Intel

5130/5140/5150 Thermal Profile

CASE MAX

TDP

CASE_MAX

_PROFILE_MIN

Tcase [°C]

0 10203040506070

Thermal Profile

y = 0.385 * x + 40

_PROFILE_MIN

1U CEK Reference Solution

Power [W]

The 2U+ CEK Intel reference thermal solution is designed to meet the Thermal Profile A for the Dual-Core Intel Xeon Processor 5160. From Table 2-6, the three-sigma (mean+3sigma) performance of the thermal solution is computed to be 0.236°C/W and the processor local ambient temperature (T

) for this thermal solution is 40°C. Hence,

the Thermal Profile equation for this thermal solution is calculated as:

Xeon® Processor 5110/5120/

y = 0.299 * x + 40

TDP

Equation 2-10.y = 0.236x + 40

where,

y = Processor T x = Processor power value (W)

Figure 2-19 below shows the comparison of this reference thermal solution’s Thermal Profile to the Dual-Core Intel The 2U+ CEK solution meets the Thermal Profile A with a 1.3°C margin at the lower end (P

_PROFILE_MIN

) and 1.1°C margin at the upper end (TDP). By designing to Thermal Profile A, it is ensured that no measurable performance loss due to TCC activation is observed under the given environmental conditions.

value (°C)

CASE

Xeon® Processor 5160 Thermal Profile A specification.

Dual-Core Intel® Xeon® Processor 5100 Series Thermal/Mechanical Design Guide 41

Thermal/Mechanical Reference Design

Figure 2-19. 2U+CEK Thermal Adherence to Dual-Core Intel Xeon Processor 5160 Thermal

Profile A

CASE MAX_A

TDP

TDP T

CASE_MAX

_PROFILE_MIN

Tcase [°C]

0 102030405060708090

Thermal Pro file A

y = 0.231 * x + 41.5

_PROFILE_MIN

2U+ CEK Reference Solution

y = 0.236 * x + 40

Power [W]

TDP

The 1U CEK Intel reference thermal solution is designed to meet the Thermal Profile B for the Dual-Core Intel® Xeon® Processor 5160. From Table 2-6 the three-sigma (mean+3sigma) performance of the thermal solution is computed to be 0.299°C/W and the processor local ambient temperature (T

) for this thermal solution is 40°C. Hence,

the Thermal Profile equation for this thermal solution is calculated as:

Equation 2-11.y = 0.299x + 40

where,

y = Processor T

value (°C)

CASE

x = Processor power value (W)

Figure 2-20 below shows the comparison of this reference thermal solution’s Thermal Profile to the Dual-Core Intel

Xeon® Processor 5160 Thermal Profile B specification. The 1U CEK solution meets the Thermal Profile B with 1.9°C margin at the lower end (P

_PROFILE_MIN

) and 1.1°C margin at the upper end (TDP). However, as explained in

Section 2.2.7, designing to Thermal Profile B results in increased TCC activation and

measurable performance loss for the processor.

42 Dual-Core Intel® Xeon® Processor 5100 Series Thermal/Mechanical Design Guide

Thermal/Mechanical Reference Design

Figure 2-20. 1U CEK Thermal Adherence to Dual-Core Intel Xeon Processor 5160 Thermal

Profile B

CASE MAX_B

TDP

CASE_MAX

_PROFILE_MIN

Tcase [°C]

0 1020304050607080

Thermal Profile B

y = 0.282 * x + 42.4

_PROFILE_MIN

1U CEK Reference Solution

y = 0.299 * x + 40

Power [W]

TDP

2.4.7 Components Overview

2.4.7.1 Heatsink with Captive Screws and Standoffs

The CEK reference heatsink uses snapped-fin technology for its design. It consists of a copper base and copper fins with Shin-Etsu* G751 thermal grease as the TIM. The mounting screws and standoffs are also made captive to the heatsink base for ease of handling and assembly as shown in Figure 2-21 and Figure 2-22 for the 2U+ and 1U heatsinks, respectively.

Figure 2-21. Isometric View of the 2U+ CEK Heatsink

Note: Refer to Appendix A for more detailed mechanical drawings of the heatsink.

Dual-Core Intel® Xeon® Processor 5100 Series Thermal/Mechanical Design Guide 43

Figure 2-22. Isometric View of the 1U CEK Heatsink

Note: Refer to Appendix A for more detailed mechanical drawings of the heatsink.

The function of the standoffs is to provide a bridge between the chassis and the heatsink for attaching and load carrying. When assembled, the heatsink is rigid against the top of the standoff, and the standoff is rigid to a chassis standoff with the CEK spring firmly sandwiched between the two. In dynamic loading situations the standoff carries much of the heatsink load, especially in lateral conditions, when compared to the amount of load transmitted to the processor package. As such, it is comprised of steel. The distance from the bottom of the heatsink to the bottom of the standoff is

10.26 mm [0.404 in.] for a board thickness of 1.57 mm [0.062 in]. The standoff will need to be modified for use in applications with a different b o ard thickness, as defined in Section 2.4.4.2.

Thermal/Mechanical Reference Design

The function of the screw is to provide a rigid attach method to sandwich the entire CEK assembly together, activating the CEK spring under the baseboard, and thus providing the TIM preload. A screw is an inexpensive, low profile solution that does not negatively impact the thermal performance of the heatsink due to air blockage. Any fastener (i.e. head configuration) can be used as long as it is of steel construction; the head does not interfere with the heatsink fins, and is of the correct length of 20.64 mm [0.8125 in.].

Although the CEK heatsink fits into the legacy volumetric keep-in, it has a larger footprint due to the elimination of retention mechanism and clips used in the older enabled thermal/mechanical components. This allows the heatsink to grow its base and fin dimensions, further improving the thermal performance. A drawback of this enlarged size and use of copper for both the base and fins is the increased weight of the heatsink. The retention scheme employed by CEK is designed to support heavy heatsinks (approximately up to 1000 grams) in cases of shock, vibration and installation as explained in Appendix D. Some of the thermal and mechanical characteristics of the CEK heatsinks are shown in Table 2-8.

Table 2-8. CEK Heatsink Thermal Mechanical Characteristics

Size

2U+ 50.80 [2.00] 1.0 [2.2] 45.9 [27] 0.229 0.0024 45.3 [0.182]

1U 27.00 [1.06] 0.53 [1.2] 25.5 [15] 0.290 0.0028 82.4 [0.331]

Height Weight

(mm) [in.] (kg) [lbs]

Target

Airflow

Through Fins

/hr)

[CFM]

Mean Ψca

(° C/W) (° C/W) (Pa) [in H

Standard

Deviation Ψ

Pressure Drop

44 Dual-Core Intel® Xeon® Processor 5100 Series Thermal/Mechanical Design Guide

Thermal/Mechanical Reference Design

2.4.7.2 Thermal Interface Material (TIM)

A TIM must be applied between the package and the heatsink to ensure thermal conduction. The CEK reference design uses Shin-Etsu* G751 thermal grease.

The recommended grease dispenses weight to ensure full coverage of the processor IHS is given below. For an alternate TIM, full coverage of the entire processor IHS is recommended.

Table 2-9. Recommended Thermal Grease Dispense Weight

Processor Minimum Maximum Units Notes

TIM Dispense weight 400 mg Shin-Etsu* G751. Dispense

TIM loading provided

by CEK

It is recommended that you use thermally conductive grease. Thermally conductive grease requires special handling and dispense guidelines. The following guidelines apply to Shin-Etsu G751 thermal grease. For guidance with your specific application, please contact the vendor. Vendor information is provided in Appendix E. The use of a semi-automatic dispensing system is recommended for high volume assembly to ensure an accurate amount of grease is dispensed on top of the IHS prior to assembly of the heatsink. A typical dispense system consists of an air pressure and timing controller, a hand held output dispenser, and an actuation foot switch. Thermal grease in cartridge form is required for dispense system compatibility. A precision scale with an accuracy of ±5 mg is recommended to measure the correct dispense weight and set the corresponding air pressure and duration. The IHS surface should be free of foreign materials prior to grease dispense.

18 80

133

lbf

weight is an approximate

target.

Generated by the CEK.

Additional recommendations include recalibrating the dispense controller settings after any two hour pause in grease dispense. The grease should be dispensed just prior to heatsink assembly to prevent any degradation in material performance. Finally, the thermal grease should be verified to be within its recommended shelf life before use.

The CEK reference solution is designed to apply a compressive load of up to 200 N [45 lbf] on the TIM to improve the thermal performance.

2.4.7.3 CEK Spring

The CEK spring, which is attached on the secondary side of the baseboard, is made from 0.80 mm [0.0315 in.] thick 301 stainless steel half hard. Any future versions of the spring will be made from a similar material. The CEK spring has four embosses which, when assembled, rest on the top of the chassis standoffs. The CEK spring is located between the chassis standoffs and the heatsink standoffs. The purpose of the CEK spring is to provide compressive preload at the TIM interface when the baseboard is pushed down upon it. This spring does not function as a clip of any kind. The two tabs on the spring are used to provide the necessary compressive preload for the TIM when the whole solution is assembled. The tabs make contact on the secondary side of the baseboard. In order to avoid damage to the contact locations on the baseboard, the tabs are insulated with a 0.127 mm [0.005 in.] thick Kapton* tape (or equivalent).

Figure 2-23 shows an isometric view of the CEK spring design.

Dual-Core Intel® Xeon® Processor 5100 Series Thermal/Mechanical Design Guide 45

Figure 2-23. CEK Spring Isometric View

Thermal/Mechanical Reference Design

Figure 2-24. Isometric View of CEK Spring Attachment to the Base Board

Secondary

Please refer to Appendix A for more detailed mechanical drawings of the CEK spring. Also, the baseboard keepout requirements shown in Appendix A must be met to use this CEK spring design.

Primary

2.4.8 Boxed Active Thermal Solution for the Dual-Core Intel Xeon Processor 5100 Series

Intel will provide a 2U passive and a 1U passive / active heatsink solution for the boxed Dual-Core Intel Xeon Processor 5100 Series. This active heatsink solution is primarily designed to be used in a pedestal chassis where sufficient air inlet space is present and side directional airflow is not an issue. This active heatsink solution consists of a 4 wire PWM fan and a 1U passive heatsink compatible with 1U form factors both mechanically and thermally. These solutions are intended for system integrators who build systems

46 Dual-Core Intel® Xeon® Processor 5100 Series Thermal/Mechanical Design Guide

Thermal/Mechanical Reference Design

from components available through distribution channels. The retention solution used for these products is called the CEK. The CEK base is compatible with all the heatsink solutions.

Figure 2-25 provides a representation of the active CEK solution. This design is based

on a 4-pin PWM PECI/DTS controlled active fan heatsink solution. PWM (Pulse Width Modulation also synonymous with Pulse Duration Modulation PDM) is a modulation in which the duration of pulse is varied in accordance with some characteristic of the modulating signal. This new solution is being offered to help provide better control over pedestal chassis acoustics. This is achieved though accurate measurement of processor temperature through the processor’s Digital Thermal Sensor (DTS) temperature. Fan RPM is modulated through the use an ASIC (Application Specific Integrated Circuit) located on the serverboard, that sends out a PWM control signal to the 4 connector labeled as Control.

This heatsink solution also requires a constant +12 V supplied to pin 2 and does not support variable voltage control or 3-pin PWM control. If no PWM signal is detected on

the 4

pin this heatsink solution will revert back to thermistor control mode,

supporting both the 4-wire PWM and standard 3-wire ambient air control methods. The active heatsink solution will not exceed a mass of approximately 1050 grams. Note

that this is per processor, so a dual processor system will have up to approximately 2100 grams total mass in the heatsinks. This large mass will require a minimum chassis stiffness to be met in order to withstand force during shock and vibration.

pin of the

Figure 2-25. Boxed Active CEK Heatsink Solutions with PWM/DTS Control

(Representation Only)

Clearance is required around the heatsink to ensure unimpeded airflow for proper cooling. The physical baseboard keepout requirements for the active solution are the same as the passive CEK solution shown in Appendix A. Refer to Figure A-18 through

Figure A-20 for additional details on the active CEK thermal solution volumetrics.

2.4.8.1 Fan Power Supply

The active heatsink includes a fan, which requires a +12 V power supply. Platforms must provide a matched fan power header to support the boxed processor. Table 2-10 contains specifications for the input and output signals at the heatsink fan connector.

Dual-Core Intel® Xeon® Processor 5100 Series Thermal/Mechanical Design Guide 47

Thermal/Mechanical Reference Design

The fan outputs a SENSE signal, an open-collector output, which pulses at a rate of two pulses per fan revolution. A baseboard pull-up resistor provides VCC to match the baseboard-mounted fan speed monitor requirements, if applicable. Use of the SENSE signal is optional. If the SENSE signal is not used, pin 3 of the connector should be tied to GND.

It is recommended that a 4 pin fan header be used on the baseboard, in addition to, a control ASIC that can send a PWM signal to the active fan heatsink solution on the 4 pin, at a nominal 25 KHz frequency. If a 3-pin CPU fan header is used instead, the active fan heatsink solution will revert back to an automatic ambient air temperature control mode.

The fan power header on the baseboard must be positioned to allow the fan heatsink power cable to reach it. The fan power header identification and location must be documented in the supplier’s platform documentation, or on the baseboard itself. The baseboard fan power header should be positioned within 177.8 mm [7 in.] from the center of the processor socket.

Table 2-10. Fan Specifications (Boxed 4-wire PWM/DTS Heatsink Solution)

Description Min

+12V: 12 Volt Fan Power

SENSE: SENSE Frequency 2 2 2 2 Pulses per fan revolution 1

Note: System board should pull this pin up to VCC with a resistor.

Supply

IC: Fan Current Draw N/A 1.25 1.5 1.5 A

10.8 12 12 13.2 V

Typ

Steady

Max

Steady

Max

Startup

Unit Notes

Figure 2-26. Fan Cable Connection (Active CEK)

Table 2-11. Fan Cable Connector Pin Out (Active CEK)

Pin Number Signal Color

1 Ground (Constant) Black 2 Power (+12 V) Yellow 3 Signal: 2 pulses per revolution Green 4 Control 21 KHz - 28 KHz Blue

2.4.8.2 Systems Considerations Associated with the Active CEK

This heatsink was designed to help pedestal chassis users to meet the processor thermal requirements without the use of chassis ducting. It may be necessary to implement some form of chassis air guide or air duct to meet the T ° C depending on the pedestal chassis layout. Also, while the active heatsink solution is designed to mechanically fit into a 2U chassis, it may require additional space at the top of the heatsink to allow sufficient airflow into the heatsink fan. Therefore, additional

48 Dual-Core Intel® Xeon® Processor 5100 Series Thermal/Mechanical Design Guide

temperature of 40

Thermal/Mechanical Reference Design

design criteria may need to be considered if this heatsink is used in a 2U rack mount chassis, or in a chassis that has drive bay obstructions above the inlet to the fan heatsink.

Thermal Profile A should be used to help determine the thermal performance of the platform. The primary recommended control method for this solution is using pulse width modulation control. This control method requires the motherboard provide the correct PWM duty cycle to the active fan heatsink solution to properly follow the thermal profile. If no PWM signal is detected the active heatsink solution will default back to a thermistor controlled mode and the fan will automatically adjust fan RPM to meet the thermal profile.

It is critical to supply a constant +12 V to the fan header so that the active CEK heatsink solution can operate properly . If a system board h as a jumper setting to select either a constant +12 V power to the fan header or a variable voltage, it is strongly recommended that the jumper be set by default to the constant +12 V setting.

It is recommended that the ambient air temperature outside of the chassis be kept at or below 35 °C. The air passing directly over the processor heatsink should not be preheated by other system components. Meeting the processor’s temperature specification is the responsibility of the system integrator.

2.4.8.3 Boxed Processor Contents

A direct chassis attach method must be used to avoid problems related to shock and vibration, due to the weight of the heatsink required to cool the processor. The board must not bend beyond specification in order to avoid damage. The boxed processor contains the components necessary to solve both issues. The boxed processor will include the following items:

• Dual-Core Intel X eon

Processor 5100 Series

• Unattached heatsink solution

• 4 screws, 4 springs, and 4 heatsink standoffs (all captive to the heatsink)

• Thermal Interface Material (pre-applied on heatsink)

• Installation Manual

•Intel Inside

logo

The other items listed in Figure 2-14 that are required to com plete this solution will be shipped with either the chassis or boards. They are as follows:

• CEK Spring (supplied by baseboard vendors)

• Heatsink standoffs (supplied by chassis vendors)

Dual-Core Intel® Xeon® Processor 5100 Series Thermal/Mechanical Design Guide 49

Thermal/Mechanical Reference Design

50 Dual-Core Intel® Xeon® Processor 5100 Series Thermal/Mechanical Design Guide

Mechanical Drawings

A Mechanical Drawings

The mechanical drawings included in this appendix refer to the thermal mechanical enabling components for the Dual-Core Intel Xeon Processor 5100 Series.

Note: Intel reserves the right to make changes and modifications to the design as necessary.

Table A-1. Mechanical Drawing List

Drawing Description Figure Number

“2U CEK Heatsink (Sheet 1 of 4)” Figure A-1 “2U CEK Heatsink (Sheet 2 of 4)” Figure A-2 “2U CEK Heatsink (Sheet 3 of 4)” Figure A-3 “2U CEK Heatsink (Sheet 4 of 4)” Figure A-4 “CEK Spring (Sheet 1 of 3)” Figure A-5 “CEK Spring (Sheet 2 of 3)” Figure A-6 “CEK Spring (Sheet 3 of 3)” Figure A-7 “Baseboard Keepout F ootprint Definition and Height R estrictions fo r Enabling Components

(Sheet 1 of 6)” “Baseboard Keepout F ootprint Definition and Height R estrictions fo r Enabling Components

(Sheet 2 of 6)” “Baseboard Keepout F ootprint Definition and Height R estrictions fo r Enabling Components

(Sheet 3 of 6)” “Baseboard Keepout F ootprint Definition and Height R estrictions fo r Enabling Components

(Sheet 4 of 6)” “Baseboard Keepout F ootprint Definition and Height R estrictions fo r Enabling Components

(Sheet 5 of 6)” “Baseboard Keepout F ootprint Definition and Height R estrictions fo r Enabling Components

(Sheet 6 of 6)” “1U CEK Heatsink (Sheet 1 of 4)” Figure A-14 “1U CEK Heatsink (Sheet 2 of 4)” Figure A-15 “1U CEK Heatsink (Sheet 3 of 4)” Figure A-16 “1U CEK Heatsink (Sheet 4of 4)” Figure A-17 “Active CEK Thermal Solution Vo lumetric (Sheet 1 of 3)” Figure A-18 “Active CEK Thermal Solution Vo lumetric (Sheet 2 of 3)” Figure A-19 “Active CEK Thermal Solution Vo lumetric (Sheet 3 of 3)” Figure A-20

Figure A-8

Figure A-9

Figure A-10

Figure A-11

Figure A-12

Figure A-13

Dual-Core Intel® Xeon® Processor 5100 Series Thermal/Mechanical Design Guide 51

Figure A-1. 2U CEK Heatsink (Sheet 1 of 4)

Mechanical Drawings

52 Dual-Core Intel® Xeon® Processor 5100 Series Thermal/Mechanical Design Guide

Mechanical Drawings

Figure A-2. 2U CEK Heatsink (Sheet 2 of 4)

Dual-Core Intel® Xeon® Processor 5100 Series Thermal/Mechanical Design Guide 53

Figure A-3. 2U CEK Heatsink (Sheet 3 of 4)

Mechanical Drawings

54 Dual-Core Intel® Xeon® Processor 5100 Series Thermal/Mechanical Design Guide

Mechanical Drawings

Figure A-4. 2U CEK Heatsink (Sheet 4 of 4)

Dual-Core Intel® Xeon® Processor 5100 Series Thermal/Mechanical Design Guide 55

Figure A-5. CEK Spring (Sheet 1 of 3)

Mechanical Drawings

56 Dual-Core Intel® Xeon® Processor 5100 Series Thermal/Mechanical Design Guide

Mechanical Drawings

Figure A-6. CEK Spring (Sheet 2 of 3)

Dual-Core Intel® Xeon® Processor 5100 Series Thermal/Mechanical Design Guide 57

Figure A-7. CEK Spring (Sheet 3 of 3)

Mechanical Drawings

58 Dual-Core Intel® Xeon® Processor 5100 Series Thermal/Mechanical Design Guide

Mechanical Drawings

Figure A-8. Baseboard Keepout Footprint Definition and Height Restrictions for Enabling

Components (Sheet 1 of 6)

Dual-Core Intel® Xeon® Processor 5100 Series Thermal/Mechanical Design Guide 59

Mechanical Drawings

Figure A-9. Baseboard Keepout Footprint Definition and Height Restrictions for Enabling

Components (Sheet 2 of 6)

60 Dual-Core Intel® Xeon® Processor 5100 Series Thermal/Mechanical Design Guide

Mechanical Drawings

Figure A-10. Baseboard Keepout Footprint Definition and Height Restrictions for Enabling

Components (Sheet 3 of 6)

Dual-Core Intel® Xeon® Processor 5100 Series Thermal/Mechanical Design Guide 61

Mechanical Drawings

Figure A-11. Baseboard Keepout Footprint Definition and Height Restrictions for Enabling

Components (Sheet 4 of 6)

62 Dual-Core Intel® Xeon® Processor 5100 Series Thermal/Mechanical Design Guide

Mechanical Drawings

Figure A-12. Baseboard Keepout Footprint Definition and Height Restrictions for Enabling

Components (Sheet 5 of 6)

Dual-Core Intel® Xeon® Processor 5100 Series Thermal/Mechanical Design Guide 63

Mechanical Drawings

Figure A-13. Baseboard Keepout Footprint Definition and Height Restrictions for Enabling

Components (Sheet 6 of 6)

64 Dual-Core Intel® Xeon® Processor 5100 Series Thermal/Mechanical Design Guide

Mechanical Drawings

Figure A-14. 1U CEK Heatsink (Sheet 1 of 4)

Dual-Core Intel® Xeon® Processor 5100 Series Thermal/Mechanical Design Guide 65

Figure A-15. 1U CEK Heatsink (Sheet 2 of 4)

Mechanical Drawings

66 Dual-Core Intel® Xeon® Processor 5100 Series Thermal/Mechanical Design Guide

Mechanical Drawings

Figure A-16. 1U CEK Heatsink (Sheet 3 of 4)

Dual-Core Intel® Xeon® Processor 5100 Series Thermal/Mechanical Design Guide 67

Figure A-17. 1U CEK Heatsink (Sheet 4of 4)

Mechanical Drawings

68 Dual-Core Intel® Xeon® Processor 5100 Series Thermal/Mechanical Design Guide

Mechanical Drawings

Figure A-18. Active CEK Thermal Solution Volumetric (Sheet 1 of 3)

Dual-Core Intel® Xeon® Processor 5100 Series Thermal/Mechanical Design Guide 69

Figure A-19. Active CEK Thermal Solution Volumetric (Sheet 2 of 3)

Mechanical Drawings

70 Dual-Core Intel® Xeon® Processor 5100 Series Thermal/Mechanical Design Guide

Mechanical Drawings

Figure A-20. Active CEK Thermal Solution Volumetric (Sheet 3 of 3)

Dual-Core Intel® Xeon® Processor 5100 Series Thermal/Mechanical Design Guide 71

Mechanical Drawings

72 Dual-Core Intel® Xeon® Processor 5100 Series Thermal/Mechanical Design Guide

Heatsink Clip Load Methodology

B Heatsink Clip Load

Methodology

B.1 Overview

This section describes a procedure for measuring the load applied by the heatsink/clip/ fastener assembly on a processor package.

This procedure is recommended to verify the preload is within the design target range for a design, and in different situations. For example:

• Heatsink preload for the LGA771 socket.

• Quantify preload degradation under bake conditions.

Note: This document reflects the current metrology used by Intel. Intel is continuously

exploring new ways to improve metrology. Updates will be provided later as this document is revised as appropriate.

B.2 Test Preparation

B.2.1 Heatsink Preparation

Three load cells are assembled into the base of the heatsink under test, in the area interfacing with the processor Integrated Heat Spreader (IHS), using load cells equivalent to those listed in Section B.2.2.

To install the load cells, machine a pocket in the heatsink base, as shown in Figure B-1 and Figure B-2. The load cells should be distributed evenly, as close as possible to the pocket walls. Apply wax around the circumference of each load cell and the surface of the pocket around each cell to maintain the load cells in place during the heatsink installation on the processor and motherboard.

The depth of the pocket depends on the height of the load cell used for the test. It is necessary that the load cells protrude out of the heatsink base. However, this protrusion should be kept minimal, as it will create an additional load offset since the heatsink base is artificially raised. The measurement load offset depends on the whole assembly stiffness (that is, motherboard, clip, fastener, and so forth). F or example , the Dual-Core Intel Xeon Processor 5100 Series CEK Reference Heatsink Design clip and fasteners assembly have a stiffness of around 160 N/mm [915 lb/in]. If the resulting protrusion is 0.038 mm [0.0015”], then a extra load of 6.08 N [1.37 lb] will be created, and will need to be subtracted from the measured load. Figure B-3 shows an example using the Dual-Core Intel Xeon Processor 5100 Series CEK Reference Heatsink designed for the Dual-Core Intel Xeon Processor 5100 Series in the 771–land grid array (LGA) package.

Note: When optimizing the heatsink pocket depth, the variation of the load cell height should

also be taken into account to make sure that all load cells protrude equally from the heatsink base. It may be useful to screen the load cells prior to installation to minimize variation.

Dual-Core Intel® Xeon® Processor 5100 Series Thermal/Mechanical Design Guide 73

Heatsink Clip Load Methodology

Alternate Heatsink Sample Preparation

As just mentioned, making sure that the load cells have minimum protrusion out of the heatsink base is paramount to meaningful results. An alternate method to make sure that the test setup will measure loads representative of the non-modified design is:

• Machine the pocket in the heatsink base to a depth such that the tips of the load cells are just flush with the heatsink base.

• Then machine back the heatsink base by around 0.25 mm [0.01”], so that the load cell tips protrude beyond the base.

Proceeding this way, the original stack height of the heatsink assembly should be preserved. This should not affect the stiffness of the heatsink significantly.

Figure B-1. Load Cell Installation in Machined Heatsink Base Pocket -- Bottom View

Heatsink Base

Heatsink Base Pocket

Pocket

Diam et er ~

Diam et er ~ 29 mm

29 mm [~1.15”]

[~1.15”]

Package IHS

Package IHS Outline (Top

Outline (Top Surface)

Surface)

Load

Load Cells

Cells

74 Dual-Core Intel® Xeon® Processor 5100 Series Thermal/Mechanical Design Guide

Heatsink Clip Load Methodology

Load Cells (3x)

Preload Fixture (copper core with milled out pocket)

Figure B-2. Load Cell Installation in Machined Heatsink Base Pocket -- Side View

Wax to maintain load cell in

Wax to maintain load cell in position during heatsink

Height of

Height of pocket ~ height

pocket ~ height of selected

of selected load cell

load cell

position during heatsink installation

installation

Figure B-3. Preload Test Configuration

Dual-Core Intel® Xeon® Processor 5100 Series Thermal/Mechanical Design Guide 75

B.2.2 Typical Test Equipment

For the heatsink clip load measurement, use equivalent test equipment to the one listed Table B-1.

Table B-1. Typical Test Equipment

Item Description Part Number (Model)

Load cell Notes: 1, 5

Data Logger (or scanner)

Notes: 2, 3, 4

Notes:

1. Select load range depending on expected load level. It is usually better, whenever possible, to operate in the high end of the load cell capability. Check with your load cell vendor for further information.

2. Since the load cells are calibrated in terms of mV/V, a data logger or scanner is required to supply 5 volts DC excitation and read the mV response. An automated model will take the sensitivity calibration of the load cells and convert the mV output into pounds.

3. With the test equipment listed above, it is possible to automate data recording and control with a 6101-PCI card (GPIB) added to the scanner, allowing it to be connected to a PC running LabVIEW* or Vishay's StrainSmart* software.

4. IMPORTANT: In addition to just a zeroing of the force reading at no applied load, it is important to calibrate the load cells against known loads. Load cells tend to drift. Contact your load cell vendor for calibration tools and procedure informa tion.

5. When measuring loads under thermal stress (bake for example), load cell thermal capability must be checked, and the test setup must integrate any hardware used along with the load cell. For example, the Model 13 load cells are temperature compensated up to 71°C, as long as the compensation package (spliced into the load cell's wiring) is also placed in the temperature chamber. The load cells can handle up to 121 °C (operating), but their uncertainty increases according to 0.02% rdg/°F.

Honeywell*-Sensotec* Model 13 subminiature load cells, compression only

Select a load range depending on load level being tested.

www.sensotec.com

Vishay* Measurements Group Model 6100 scanner with a 6010A strain card (one card required per channel).

Heatsink Clip Load Methodology

AL322BL

Model 6100

B.2.3 Test Procedure Examples

The following sections give two examples of load measurement. However, this is not meant to be used in mechanical shock and vibration testing.

Any mechanical device used along with the heatsink attach mechanism will need to be included in the test setup (i.e., back plate, attach to chassis, and so forth).

Prior to any test, make sure that th e load cell has been calibrated against known loads, following load cell vendor’s instructions.

B.2.4 Time-Zero, Room Temperature Preload Measurement

1. Pre-assemble mechanical components on the board as needed prior to mounting the motherboard on an appropriate support fixture that replicate the board attach to a target chassis.

For example: If the attach mechanism includes fixtures on the back side of the board, those must be included, as the goal of the test is to measure the load provided by the actual heatsink mechanism.

2. Install the test vehicle in the socket.

3. Assemble the heatsink reworked with the load cells to motherboard as shown for the Dual-Core Intel Xeon Processor 5100 Series CEK -reference heatsink example in

Figure B-3, and actuate attach mechanism.

4. Collect continuous load cell data at 1 Hz for the duration of the test. A minimum time to allow the load cell to settle is generally specified by the load cell vendors

76 Dual-Core Intel® Xeon® Processor 5100 Series Thermal/Mechanical Design Guide

Heatsink Clip Load Methodology

(often on the order of 3 minutes). The time zero reading should be taken at the end of this settling time.

5. Record the preload measurement (total from all three load cells) at the target time and average the values over 10 seconds around this target time as well, i.e. in the interval for example over [target time – 5 seconds; target time + 5 seconds].

B.2.5 Preload Degradation under Bake Conditions

This section describes an example of testing for potential clip load degradation under bake conditions.

1. Preheat thermal chamber to target temperature (45 ºC or 85 ºC for example).

2. Repeat time-zero, room temperature preload measurement.

3. Place unit into preheated thermal chamber for specified time.

4. Record continuous load cell data as follows: Sample rate = 0.1 Hz for first 3 hrs Sample rate = 0.01 Hz for the remainder of the bake test

5. Remove assembly from thermal chamber and set into room temperature conditions

6. Record continuous load cell data for next 30 minutes at sample rate of 1 Hz.

Dual-Core Intel® Xeon® Processor 5100 Series Thermal/Mechanical Design Guide 77

Heatsink Clip Load Methodology

78 Dual-Core Intel® Xeon® Processor 5100 Series Thermal/Mechanical Design Guide

Safety Requirements

C Safety Requirements

Heatsink and attachment assemblies shall be consistent with the manufacture of units that meet the safety standards:

1. UL Recognition-approved for flammability at the system level. All mechanical and thermal enabling components must be a minimum UL94V-2 approved.

2. CSA Certification. All mechanical and thermal enabling components must have CS A certification.

3. Heatsink fins must meet the test requirements of UL1439 for sharp edges.

Dual-Core Intel® Xeon® Processor 5100 Series Thermal/Mechanical Design Guide 79

Safety Requirements

80 Dual-Core Intel® Xeon® Processor 5100 Series Thermal/Mechanical Design Guide

Quality and Reliability Requirements

D Quality and Reliability

Requirements

D.1 Intel Verification Criteria for the Reference

Designs

D.1.1 Reference Heatsink Thermal Verification

The Intel reference heatsinks will be verified within specific boundary conditions using a TTV and the methodology described in the Intel® Xeon® Processor Family Thermal Test Vehicle User's Guide.

The test results, for a number of samples, are reported in terms of a worst-case mean + 3σ value for thermal characterization parameter using real processors (based on the TTV correction offset).

D.1.2 Environmental Reliability Testing

D.1.2.1 Structural Reliability Testing

The Intel reference heatsinks will be tested in an assembled condition, along with the LGA771 Socket. Details of the Environmental Requirements, and associated stress tests, can be found in the LGA771 Socket Mechanical Design Guide.

The use condition environment definitions provided in Table D-1 are based on speculative use condition assumptions, and are provided as examples only.

Dual-Core Intel® Xeon® Processor 5100 Series Thermal/Mechanical Design Guide 81

Table D-1. Use Conditions Environment

Quality and Reliability Requirements

Use Environment

Shipping and Handling

Speculative Stress

Condition

Mechanical Shock

• System-level

•Unpackaged

•Trapezoidal

• 25 g

• velocity change is based on packaged weight

Product Weight (lbs)

< 20 lbs 20 to > 40 40 to > 80 80 to < 100 100 to <

120 ≥120

†

Change in veloci ty is based upon a 0.5 coefficient of restitution.

Random Vibration

• System Level

•Unpackaged

• 5 Hz to 500 Hz

• 2.20 g RMS random

• 5 Hz @ .001 g 20 Hz @ 0.01 g (slope up)

• 20 Hz to 500 Hz @ 0.01

/Hz (flat)

• Random control limit tolerance is ± 3 dB

Nonpalletized Product Velocity

†

Change sec)

250 225 205 175 145 125

/Hz to

/Hz

(in/

Example Use

Condition

Total of 12 drops per system:

•2 drops per axis

•± direction

Total per system:

• 10 minutes per axis

•3 axes

Example 7-Yr

Stress Equiv.

n/a n/a

Example 10-

Yr Stress

Equiv.

Note: In the case of a discrepancy, information in the most recent LGA771 Socket Mechanical Design

Guidelines supersedes that in the Table D-1 above.

D.1.2.2 Recommended Test Sequence

Each test sequence should start with components (that is, baseboard, heatsink assembly, and so forth) that have not been previously submitted to any reliability testing.

The test sequence should always start with a visual inspection after assembly, and BIOS/Processor/memory test. The stress test should be then followed by a visual inspection and then BIOS/Processor/memory test.

D.1.2.3 Post-Test Pass Criteria

The post-test pass criteria are:

1. No significant physical damage to the heatsink and retention hardware.

82 Dual-Core Intel® Xeon® Processor 5100 Series Thermal/Mechanical Design Guide

Quality and Reliability Requirements

2. Heatsink remains seated and its bottom remains mated flatly against the IHS surface. No visible gap between the heatsink base and processor IHS. No visible tilt of the heatsink with respect to the retention hardware.

3. No signs of physical damage on baseboard surface due to impact of heatsink.

4. No visible physical damage to the processor package.

5. Successful BIOS/Processor/memory test of post-test samples.

6. Thermal compliance testing to demonstrate that the case temperature specification can be met.

D.1.2.4 Recommended BIOS/Processor/Memory Test Procedures

This test is to ensure proper operation of the product before and after environmental stresses, with the thermal mechanical enabling components assembled. The test shall be conducted on a fully operational baseboard that has not been exposed to any battery of tests prior to the test being considered.

Testing setup should include the following components, properly assembled and/or connected:

• Appropriate system baseboard.

• Processor and memory.

• All enabling components, including socket and thermal solution parts.

The pass criterion is that the system under test shall successfully complete the checking of BIOS, basic processor functions and memory, without any errors. Intel PC Diags is an example of software that can be utilized for this test.

D.1.3 Material and Recycling Requirements

Material shall be resistant to fungal growth. Examples of non-resistant materials include cellulose materials, animal and vegetable based adhesives, grease, oils, and many hydrocarbons. Synthetic materials such as PVC formulations, certain polyurethane compositions (e.g. polyester and some polyethers), plastics which contain organic fillers of laminating materials, paints, and varnishes also are susceptible to fungal growth. If materials are not fungal growth resistant, then MIL-STD-810E, Method 508.4 must be performed to determine material performance.

Material used shall not have deformation or degradation in a temperature life test. Any plastic component exceeding 25 grams should be recyclable per the European Blue

Angel recycling standards. The following definitions apply to the use of the terms lead-free, Pb-free, and RoHS

compliant. Lead-free and Pb-free: Lead has not been intentionally added, but lead may still

exist as an impurity below 1000 ppm. RoHS compliant: Lead and other materials banned in RoHS Directive are either (1)

below all applicable substance thresholds as proposed by the EU or (2) an approved/ pending exemption applies.

Note: RoHS implementing details are not fully defined and may change.

Dual-Core Intel® Xeon® Processor 5100 Series Thermal/Mechanical Design Guide 83

Quality and Reliability Requirements

84 Dual-Core Intel® Xeon® Processor 5100 Series Thermal/Mechanical Design Guide

Enabled Suppliers Information

EEnabled Suppliers

Information

E.1 Supplier Information

E.1.1 Intel Enabled Suppliers

The Intel reference enabling solution for Dual-Core Intel Xeon Processor 5100 Series is preliminary. The Intel reference solutions have not been verified to meet the criteria outlined in Appendix D. Customers can purchase the Intel reference thermal solution components from the suppliers listed in Table E-1.

For additional details, please refer to the Dual-Core Intel Xeon Processor 5100 Series thermal mechanical enabling components drawings in Appendix A.

Table E-1. Suppliers for the Dual-Core Intel Xeon Processor 5100 Series Intel Reference

Solution (Sheet 1 of 2)

Assembly Component Description

CEK771-01-2U (for 2U, 2U+)

CEK Heatsinks

Intel Reference Heatsink p/n C61708 rev03

- or -

Intel Boxed Heatsink p/n D36871

CEK Heatsink

Intel Boxed Heatsink p/n D36871

Thermal Interface Material

CEK Spring for CEK771

Intel p/n D13646 rev04

Copper Fin, Copper Base

includes PCM45F TIM+cover

Copper Fin, Copper Base

includes PCM45F TIM+cover

Grease Shin-Etsu G751

Stainless Steel 301, Kapton* Tape on Reinforced Spring Fingers

Development

Suppliers

Fujikura

CNDA 1242012

(stacked fin)

Furukawa

CNDA 65755

(Crimped fin)

CNDA 75610

AVC

CNDA 2085011

Supplier Contact Info

Fujikura America Ash Ooe a_ooe@fujikura.com 408-748-6991

Fujikura Taiwan Branch Yao-Hsien Huang yeohsien@fujikuratw.com.tw 886(2)8788-4959

Furukawa America Timothy Yu yu@FurukawaAmerica.com 408-345-1528

Furukawa Taiwan Branch Johnson Tseng Johnson@tfe.com.tw (02)2563-8148x15

Donna Hartigan (480) 893-8898

David Chao 886-2-22996390 x619 david_chao@avc.com.tw

Dual-Core Intel® Xeon® Processor 5100 Series Thermal/Mechanical Design Guide 85

Enabled Suppliers Information

Table E-1. Suppliers for the Dual-Core Intel Xeon Processor 5100 Series Intel Reference

Solution (Sheet 2 of 2)

Assembly Component Description

CEK771-01-1U (for 1U)

CEK Heatsink

Intel p/n C90546 rev02

Thermal Interface Material

CEK Spring for CEK771

Copper Fin, Copper Base

See CEK771-2U-01

Development

Suppliers

Fujikura

CNDA 1242012

(stacked fin)

Supplier Contact Info

Fujikura America Ash Ooe a_ooe@fujikura.com 408-748-6991

Fujikura Taiwan Branch Yao-Hsien Huang yeohsien@fujikuratw.com.tw 886(2)8788-4959

E.1.2 Additional Enabled Suppliers

The Intel enabled solutions for Dual-Core Intel Xeon Processor 5100 Series are preliminary. The Intel enabled solutions have not been verified to meet the criteria outlined in Appendix D. Customers can purchase the Intel enabled thermal solution components from the suppliers listed in Table E-1.

For additional details, please refer to the Dual-Core Intel Xeon Processor 5100 Series thermal mechanical enabling components drawings in Appendix A.

Table E-2. Suppliers of Alternative Thermal Solutions for the Dual-Core Intel Xeon

Processor 5100 Series

Assembly Component Description

2U Heatsink Alternative CEK

Heatsink

Copper Fin, Copper Base

Development

Suppliers

AVC

CNDA AP5281

(stacked fin)

Aavid

Thermalloy

CNDA

#2525071

CCI (Chaun-

Choung

Technology Co.

Ltd.

CNDA

#8747572

Auras CNDA

#5779699

Supplier Contact Info

David Chao david_chao@avc.com.tw 886-2022996930x7619

Jeff Brown (North America) jb@avcamerica.com 310-783-5442

David Huang huang@aavid.com 603-223-1724

Frank Hsue frank.hsu@aavid.com.tw 886-2-26989888 x306

Monica Chih monica_chih@ccic.com.tw 886-2-29952666 EXT 292

Hary Lin 714-739-5797 ackinc@aol.com

Stephen Lee stephen_lee@auras.com.tw +886-937-183-194

86 Dual-Core Intel® Xeon® Processor 5100 Series Thermal/Mechanical Design Guide

Enabled Suppliers Information

Table E-2. Suppliers of Alternative Thermal Solutions for the Dual-Core Intel Xeon

Processor 5100 Series

Assembly Component Description

1U Heatsink Alternative CEK

Heatsink

Copper Fin, Copper Base

Development

Suppliers

AVC

CNDA AP5281

ADDA

CNDA AP1249

CCI

CNDA 8747572

Auras CNDA

#5779699

CoolerMaster

CNDA

#7425225

ThermalTake

CNDA

#7429482

Supplier Contact Info

David Chao david_chao@avc.com.tw 886-2022996930x7619

Jeff Brown (North America) jb@avcamerica.com 310-783-5442

Jomei jomei@adda.com.tw 886-2-82212252x209

Monica Chih monica_chih@ccic.com.tw 886-2-29952666 EXT 292

Hary Lin 714-739-5797 ackinc@aol.com

Stephen Lee stephen_lee@auras.com.tw +886-937-183-194

Helen Wen helena_wan@coolermaster.com.tw +886 (2) 3234-0050 x235

Vic Chan vic@thermaltake.com +866 (2) 2662-6501 x213

Dual-Core Intel® Xeon® Processor 5100 Series Thermal/Mechanical Design Guide 87

Enabled Suppliers Information

88 Dual-Core Intel® Xeon® Processor 5100 Series Thermal/Mechanical Design Guide

Intel 5100 Series Instruction Manual

Specifications and Main Features

Frequently Asked Questions

User Manual

Dual-Core Intel® Xeon® Processor 5100 Series

Contents

Figures

Tables

Revision History

1 Introduction

1.1 Objective

1.2 Scope

1.3 References

Table 1-1. Reference Documents

1.4 Definition of Terms

Table 1-2. Terms and Descriptions (Sheet 1 of 2)

Thermal/Mechanical Reference Design

2.1 Mechanical Requirements

2.1.1 Processor Mechanical Parameters

Table 2-1. Processor Mechanical Parameters Table

2.1.2 Dual-Core Intel Xeon Processor 5100 Series Processor Package

Figure 2-1. Dual-Core Intel® Xeon® Processor 5100 Series Mechanical Drawing

2.1.3 Dual-Core Intel Xeon Processor 5100 Series Considerations

2.2 Processor Thermal Parameters and Features

2.2.1 Thermal Control Circuit and TDP

2.2.2 Digital Thermal Sensor

2.2.3 Platform Environmental Control Interface (PECI)

2.2.4 Multiple Core Special Considerations

2.2.4.1 Multiple Digital Thermal Sensor Operation

Figure 2-2. DTS Domain for Dual-Core Intel Xeon Processor 5100 Series

2.2.4.2 Thermal Monitor for Multiple Core Products

2.2.4.3 Fan Speed Control for Dual-Core Intel Xeon Processor 5100 Series

Figure 2-3. Fan Speed Control for Dual-Core Intel Xeon Processor 5100 Series

2.2.4.4 PROCHOT#, THERMTRIP#, and FORCEPR#

2.2.4.5 Heatpipe Orientation for Multiple Core Processors

Figure 2-4. Processor Core Geometric Center Locations

Table 2-3. Processor Core Geometric Center Dimensions

2.2.5 Thermal Profile

Figure 2-5. Thermal Profile Diagram

2.2.7 Thermal Profile Concepts for the Dual-Core Intel Xeon Processor 5100 Series

Figure 2-8. Dual Thermal Profile Diagram

2.2.8 Performance Targets

Figure 2-9. Thermal Profile for the Dual-Core Intel Xeon Processor 5148

Figure 2-11. Thermal Profiles A and B for the Dual-Core Intel® Xeon® Processor 5160

2.3 Characterizing Cooling Solution Performance Requirements

2.3.1 Fan Speed Control

2.3.2 Processor Thermal Characterization Parameter Relationships

Figure 2-13. Processor Thermal Characterization Parameter Relationships

2.3.2.1 Example

2.3.3 Chassis Thermal Design Considerations

2.3.3.1 Chassis Thermal Design Capabilities and Improvements

2.4 Thermal/Mechanical Reference Design Considerations

2.4.1 Heatsink Solutions

2.4.1.1 Heatsink Design Considerations

2.4.2 Thermal Interface Material

2.4.3 Summary

2.4.4 Assembly Overview of the Intel Reference Thermal Mechanical Design

2.4.4.1 Geometric Envelope

2.4.4.2 Assembly Drawing

Figure 2-14. Exploded View of CEK Thermal Solution Components

2.4.4.3 Structural Considerations of CEK

2.4.5 Thermal Solution Performance Characteristics

Figure 2-15. 2U+ CEK Heatsink Thermal Performance

Figure 2-16. 1U CEK Heatsink Thermal Performance

2.4.6 Thermal Profile Adherence

2.4.7 Components Overview

2.4.7.1 Heatsink with Captive Screws and Standoffs

Figure 2-21. Isometric View of the 2U+ CEK Heatsink

Figure 2-22. Isometric View of the 1U CEK Heatsink

Table 2-8. CEK Heatsink Thermal Mechanical Characteristics

2.4.7.2 Thermal Interface Material (TIM)

Table 2-9. Recommended Thermal Grease Dispense Weight

2.4.7.3 CEK Spring

Figure 2-23. CEK Spring Isometric View

Figure 2-24. Isometric View of CEK Spring Attachment to the Base Board

2.4.8 Boxed Active Thermal Solution for the Dual-Core Intel Xeon Processor 5100 Series

2.4.8.1 Fan Power Supply

Table 2-10. Fan Specifications (Boxed 4-wire PWM/DTS Heatsink Solution)

Figure 2-26. Fan Cable Connection (Active CEK)

Table 2-11. Fan Cable Connector Pin Out (Active CEK)