Dell PRECISION 7920 TOWER Service Manual

PRECISION™7920
TOWER

Technical

Guidebook

TABLE OF CONTENTS

OVE R V I E W

External Chassis and Internal Views

3-4

Motherboard Layouts

5-6

SYST E M C O N F IG U R A T I ON O P T I O N S

Operating Systems, Chipset

7

Processors

8-9

Memory including Intel Optane DC Persistent Memory

10-12

FlexBay Storage Options, Storage Configuration Flow

13-14

Graphics

15

Bays, Hard Drives and Optical Storage

16

Solid State Drives, Dell Performance Classifications and Endurance, Dell Ultra-Speed Drive PCIe Card

17-18

System Expansion Slots, External Ports/Connectors

19

Hard Drive Controllers, Communications—Network Adapter, Audio and Speakers, Keyboard and Mouse

21

Security, Misc Software, Service and Support

22

DET A I L E D E NG I N E E R I NG S P E C I F ICA T I O N S

System Dimensions (Physical), System Expansion Slots, RTX Aux graphics power requirements

23-24

System Level Environmental and Operating Conditions, PSU

25

Battery and Broadcom (formerly Avago & LSI) MegaRAID PCIe Controllers

26

Audio, Communications—Integrated LAN, add in PCI-e LAN cards

27-30

USB 3.1, Serial port and Thunderbolt 3 PCIe cards

31

PCoIP Remote Workstation Host Cards

32

Graphics cards

33–51

Hard Drives

52-57

Optical Drives

58

BIOS Default settings

59-60

Chassis Enclosure and Ventilation Requirements

61

ADD I T I O N A L I N F O R M ATI ON

Statement of Volatility (SOV)

62-64

Feb. 2021 Specifications subject to change without notice

Dell Precision 7920 Tower

DELL™ PRECISION™ 7920 TOWER TECHNICAL GUIDEBOOK

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792 0 T O WER E X T ERN A L CH A S S IS V I E W S

FRONT VIEW

1

Power button, power
light

6 USB 3.2 Gen 1

Type C port

2

Drive Activity Light 7 Universal Audio

Jack

3

SD Card Slot 8 Front Bezel Release

Latch

4

USB 3.2 Gen 1
Type A ports

9 5.25” ODD Bay

(optional)

5

USB 3.2 Gen 1
Type C port (DP/
PowerDelivery)

10 Slimline Optical Bay

BACK VIEW

1

Power Supply 9 Network Port

2

Line-Out Port 10 USB 3.2 Gen 1 Type

A Ports

3

Microphone/Line-in
Port

11 USB 3.2 Gen 1 Type

A port (DP/

PowerDelivery)

4

Serial Port 12 Mechanical Expan-

sion Slot

5

PS/2 Mouse Port 13 PCIE Expansion

Slots

6

PSU BIST 14 Side Cover Release

Latch

7

PS/2 Keyboard Port 15 PCIE expansion

slots (CPU1 re­quired)

8

Network Port (AMT
Enabled—Optional)

DELL™ PRECISION™ 7920 TOWER TECHNICAL GUIDEBOOK

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792 0 T O WER I N T ERN AL V IEW

Number Name Number Name

1

System board 6 Auxiliary PCIe power cables

2

CPU and Memory Air shroud 7 Graphics card (GPU) with aux power connector

3

Intrusion switch 8 PCIe card release latches

4

Front system fan assembly 9 Rear HDD Bezel lock/unlock button

5

Front Bezel lock/unlock button 10 Rear Fans

DELL™ PRECISION™ 7920 TOWER TECHNICAL GUIDEBOOK

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792 0 T O WER M O THERB O A RD L A Y OUT

System Board

Number Name Number Name

PCIE Gen3 Slots (right to left below) 8 Front Panel Audio connector

1

Slot 1—PCIE x8 Gen 3 (Open Ended) 9 N/A

Slot 2—PCIE x16 Gen 3 10 Piezo Speaker
Slot 3—PCIE x16 Gen 3 (wired as x1) 11 CPU 0 Fan Connector
Slot 4—PCIE x16 Gen 3 12 Power Control Connector
Slot 5—PCIE x16 Gen 3 (wired as x4) 13 Power 2 Fan Connector

2 Rear Fan 0 Connector 14 Intrusion Switch Connector
3

DIMM Slots (available only when optional CPU1 is

installed)

15 System Fan 3

4 CPU1 Socket 16 Internal Speaker Connector

5

DIMM Slots (available only when optional CPU1 is

installed)

17 DIMM Slots (CPU0)

6 Rear Fan 1 Connector 18 CPU0 Socket

7

PCIE x16 Gen 3 Slots (Slot 6 and 7) 19 System Fan 2

DELL™ PRECISION™ 7920 TOWER TECHNICAL GUIDEBOOK

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792 0 T O WER M O THERB O A RD L A Y OUT ( C ONT . )

Number Name Number Name

20

DIMM Slots (CPU0)

26

ODD Connector

21

System Fan 1

27

Front Panel USB Connector

22

N/A

28

Internal USB Port (Type A)

23

Power 1 Connector

29

2x5 USB 2.0 header for ex bay. (Requires oponal splier
cable to support 2 x USB 2.0 Type A ports)

24

CPU Fan 1 (Mid CPU Fan)

30

Power Remote (Teradici) header

25

Coin Cell Baery

31

Intel vROC® Key (oponally enables PCIe NVMe RAID)

DELL™ PRECISION™ 7920 TOWER TECHNICAL GUIDEBOOK

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SYST E M CON F I G U R AT I O N O PT I O N S

NOTE : O er in gs may v ar y by country . .

Operating Systems

CHIP S E T

Chipset Intel C621 Chipset (C620 Series)

Non-volatile memory on chipset

BIOS Configuration SPI (Serial Peripheral Interface) 256Mbit (32MB)

TPM 1.2 Security Device (Trusted Platform Module)

1

TPM 2.0 ships and is supported with Windows 10 only
Note: All systems are field upgradable to TPM 2.0 (with
firmware & BIOS updates plus Windows 10 Installation

http://www.dell.com/support/article/us/en/04/SLN300914

18KB

Non-TPM Available in select countries

NIC EEPROM

LOM configuration contained within SPI_FLASH – no dedicated LOM
EEPROM

Microsoft® Windows 10® operating system

Factory installed
Microsoft® Windows® 10 Pro for Workstations (64 bit)

Microsoft® Windows 7® operating system Microsoft® Windows 7® Professional (64 bit), EOL

Red Hat® Enterprise Linux® 7.5/8.0

Factory installed
RHEL workstation 8.0

Ubuntu 16.04/18.04

18.04 Factory Installed
Limited options supported

NeoKylin 6.5

Factory Installed –in China —limited options supported
NeoKylin is not offered on 5820 Tower systems with Intel X299 chip­sets

DELL™ PRECISION™ 7920 TOWER TECHNICAL GUIDEBOOK

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INTEL X EON C A S C ADE L AKE 2 N D GE N S CAL A B L E P R O CESSO R F AMIL Y - SP

Note: Global Standard Products (GSP) are a subset of Dell’s relationship products that are managed for availability and synchronized
transitions on a worldwide basis. They ensure the same platform is available for purchase globally. This allows customers to reduce
the number of configurations managed on a worldwide basis, thereby reducing their costs. They also enable companies to implement
global IT standards by locking in specific product configurations worldwide. The following GSP processors identified below will be
made available to Dell customers.

Note: Processor numbers are not a measure of performance. Processor availability subject to change and may vary by region/
country.

• 3200MHz memory in the 7920 Towers/Rack will not run at that frequency. It will automatically clock down to the maximum fre-

quency supported by the processor which is 2933MHz for Xeon Cascade Lake 82XX Platinum and 62XX Gold processors,
2666MHz with Xeon Cascade Lake Gold 52XX, and 2400MHz and 2133MHz speeds respectively for Silver 42XX and Bronze

32XX processors.

DELL™ PRECISION™ 7920 TOWER TECHNICAL GUIDEBOOK

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792 0 T O WER P R O CES S O R S — I N T EL X E O N SK Y L AKE S C AL AB L E PRO C E S SOR F AM IL Y - SP

Note: Global Standard Products (GSP) are a subset of Dell’s relationship products that are managed for availability and synchronized
transitions on a worldwide basis. They ensure the same platform is available for purchase globally. This allows customers to reduce
the number of configurations managed on a worldwide basis, thereby reducing their costs. They also enable companies to implement
global IT standards by locking in specific product configurations worldwide. The following GSP processors identified below will be
made available to Dell customers.

Note: Processor numbers are not a measure of performance. Processor availability subject to change and may vary by region/

country.

• 2666MHz DDR4 ECC RDIMM/LRDIMM memory will scale down to 2400MHz with Xeon Gold 51XX Series (excluding 5122) and

Xeon Silver 41XX Series and down to 2133MHz with Xeon Bronze 31XX Series Processors.

• 2933MHz DDR4 ECC RDIMM memory is not supported with Xeon Skylake SP processors

DELL™ PRECISION™ 7920 TOWER TECHNICAL GUIDEBOOK

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MEM O R Y - 2 9 3 3 M HZ A N D 32 0 0 M HZ

2666MHz and 2933MHz memory RDIMMs have now transitioned to 3200MHz. However 3200MHz memory in the 7920 Tower will not
run at that frequency. It will automatically clock down to the maximum frequency supported by the processor which is 2933MHz for
Xeon Cascade Lake 82XX Platinum and 62XX Gold processors. With Xeon Cascade Lake Gold 52XX, Silver 42XX and Bronze 32XX
processors, memory will clock down to 2666MHz, 2400MHz and 2133MHz speeds respectively. See processor page for details.
Note: Precision 7000 system memory SKU descriptions reference 2933MHz or 2666MHz based upon the maximum frequency they
can run with Xeon SP Cascade Lake or Sky Lake processors respectively.

Type: DDR4 SDRAM RDIMM/LRDIMM ECC

Max Frequency 2933MHz

DIMM Slots 24 (12 per CPU)

DIMM Capacities 8GB,16GB, 32GB, 64GB RDIMM, 128GB LRDIMM

Maximum System Memory 3.0TB with 2x “L” CPU SKUs installed)

QU AL I F I ED M E M ORY C O N FIG U R ATIO N S :

Note: Not all qualified configurations are necessarily available as standard factory installed options but are possible via CFI or memory
customer kits.

DELL™ PRECISION™ 7920 TOWER TECHNICAL GUIDEBOOK

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MEM O R Y - 2 9 3 3 M HZ A N D 32 0 0 M HZ

2666MHz and 2933MHz memory RDIMMs have now transitioned to 3200MHz. However 3200MHz memory in the 7920 Tower will not
run at that frequency. It will automatically clock down to the maximum frequency supported by the processor which is 2933MHz for
Xeon Cascade Lake 82XX Platinum and 62XX Gold processors. With Xeon Cascade Lake Gold 52XX, Silver 42XX and Bronze 32XX
processors, memory will clock down to 2666MHz, 2400MHz and 2133MHz speeds respectively. See processor page for details.
Note: Precision 7000 system memory SKU descriptions reference 2933MHz or 2666MHz based upon the maximum frequency they
can run with Xeon SP Cascade Lake or Sky Lake processors respectively.

Type: DDR4 SDRAM RDIMM/LRDIMM ECC

Max Frequency 2933MHz

DIMM Slots 24 (12 per CPU)

DIMM Capacities 8GB, 16GB,32GB 64GB RDIMM, 128GB LRDIMM

Maximum System Memory 3.0TB with 2x “L” CPU SKUs installed)

QU AL I F I ED M E M ORY C O N FIG U R ATIO N S :

Note: Not all qualified configurations are necessarily available as standard factory installed options but are possible via CFI or memory
customer kits.

DELL™ PRECISION™ 7920 TOWER TECHNICAL GUIDEBOOK

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MEM O R Y - I N T E L OP T ANE D C P ERSI S T E NT M E M ORY 2 6 6 6MH Z ( M EM O R Y MODE)

Intel Optane DC Persistent Memory is offered with select Xeon Cascade Lake processors. It runs at 2666MHz and requires standard
RDIMM memory as cache— which is not included in overall memory capacity. Intel DCPMM is supported in memory mode only on the
Precision 7920 Tower and is not “Persistent” in memory mode.

Note: 2666MHz RDIMM memory used as cache in Optane DC Persistent Memory configs has transitioned to 3200MHz RDIMM
memory as part of an industry transition. However the 3200MHz memory will automatically clock down to a maximum of 2666MHz.

Type: Intel Optane DC Persistent Memory modules

Max Frequency 2666MHz

DCPMM Capacities 128GB, 256GB, 512GB

Maximum Memory with DCPMM 1.5TB with1 CPU, up to 6.0TB with 2 CPUs (“L” SKUs)

DELL™ PRECISION™ 7920 TOWER TECHNICAL GUIDEBOOK

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1

The total amount of available memory will be less than 4GB on systems running 32-bit operating systems. The amount less depends

on the actual system configuration. To fully utilize 4GB or more of memory requires a 64-bit operating system.

792 0 T O WER F L E XB A Y S TO R A G E

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792 0 T O WER - CO N F I G URI N G STOR A G E

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GR AP H I C S

NOTE: The system supports full height (FH) cards. Up to 4 single wide or 3 double wide graphics cards (excluding the 3080/3090
graphics cards) can be supported with the 2nd CPU installed (adds two additional single width PCIe Gen 3.0 x16 slots). Some dual

and triple RTX graphics card configurations require 220V AC supply/line cord in 100-120V countries like the U.S. Canada
and Japan

Precision systems ship out of the factory with PCIe AUX graphics power connectors (dongles) as needed for the supported graphics
cards. NOTE: Dual Graphics with NVIDIA NVLink and SLI (Scalable Link Interface) options available with select cards.

Graphics Opons

High End 3D Cards

Options Graphics card PCIe AUX power connectors/dongles

Radeon Pro W5700 1x 8 pin 1x 6 pin

Radeon Pro WX 9100 - EOL 1x 8 pin 1x 6 pin

NVIDIA Quadro GV100 1x 8 pin

NVIDIA Quadro RTX 8000 1x 8 pin 1x 6 pin

NVIDIA Quadro RTX 6000 1x 8 pin 1x 6 pin

NVIDIA Quadro RTX 5000 1x 8 pin 1x 6 pin

Nvidia Consumer Graphics Cards

NVIDIA GeForce RTX 3090 – Maximum 1 card 2x 8pin

NVIDIA GeForce RTX 3080 – Maximum 1 card 2x 8pin

Mid-range 3D Cards

Options Graphics card PCIe AUX power inputs

Radeon Pro W5500 1x 6 pin

Radeon Pro WX 7100 1x 6 pin

Radeon Pro WX 5100

Radeon Pro WX 3200

NVIDIA Quadro RTX 4000 1x 8 pin

NVIDIA Quadro P2200

Entry 3D Cards

Options Graphics card PCIe AUX power inputs

NVIDIA Quadro P620

NVIDIA Quadro P400

Professional 2D Cards

DELL™ PRECISION™ 7920 TOWER TECHNICAL GUIDEBOOK

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BAY S , D RIVE S AND O P T IC AL S T OR AG E OPT I O N S

BAY S :

2x front FlexBays (0,1) support 2 drives each (tot. 4 drives)
Convertible 5.25” front FlexBay (2) can support 1x 3.5” or 2x

2.5” drives
Optional 2 rear FlexBays (4,5) can support up to 4x 3.5” or 2.5”
drives

FlexBays can support 2.5” or 3.5” drives
Standard (non PCIe backplane) systems ship with all 4 drive bays
populated with sleds/carriers that support 2.5” or 3.5” drives.
Empty 2nd bay on PCIe backplane systems have standard sleds.
FlexBays 0 and 1 (with PCIe backplanes) can support up to 4x
M.2 (M.2 module/carrier) or U.2 PCIe NVMe SSDs

Maximum 2.5”/3.5”Hard Drives/SSDs supported

10x 2.5” or 3.5” with MegaRAID 9460-16i controller.
Slimline bay is not available with 9 or 10 drives installed

Maximum front FlexBay M.2/U.2 PCIe NVMe SSDs supported

Up to 4x drives with integrated Intel controller and two CPUs
Up to 4x drives with MegaRAID 9460 NVMe controller option

Internal M.2 PCIe NVMe SSDs supported on Dell Ultra-Speed

Drive PCIe cards

Up to 8x on two cards with dual CPUs

Slimline Bay

1x - supports slimline optical or CAC/PIV Card Reader
Not available with 9x or 10x hard drives populated

Optical Drives Supported 1x slimline, or 1x HH in 5.25” FlexBay 2

DRI V E S :

3.5” Hard Drives:

3.5” 4TB SAS 7200 RPM nearline HDD X

3.5” 12TB 7200 RPM SATA Enterprise HDD X

3.5” 8TB 7200 RPM SATA Enterprise HDD X

3.5” 4TB 7200 RPM SATA Enterprise HDD X

3.5” 2TB SATA 7200 RPM HDD X

3.5” 1TB SATA 7200 RPM HDD X

2. 5 ” H A R D DR I V E S :

2.5” 500GB SATA 7200 RPM HDD X

2.5” 900GB SAS 12Gb/s 15K RPM HDD X

2.5” 600GB SAS 12Gb/s 15K RPM HDD X

2.5” 300GB SAS 12Gb/s 15K RPM HDD X

1

Discs burned with this drive may not be compatible with some existing drives and players; using DVD+R media provides maximum

compatibility.

2

DVD-ROM drives may have write-capable hardware that has been disabled via firmware modifications.

OPTI C A L D RIV E S :

Slimline DVD+/-RW

1

SATA 1.5Gbit/s X

Slimline DVD-ROM1 SATA 1.5Gbit/s X

Half height BD-RE SATA - EOL June 2021 X

5.25” DVD+/-RW

1

SATA 1.5Gbit/s X

MEDI A C A R D R E A D E R :

Front panel—integrated SD card reader X

DELL™ PRECISION™ 7920 TOWER TECHNICAL GUIDEBOOK

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SOLI D S T AT E D R IVE S

2.5” SATA SSDs:

2.5" 1.92TB SATA Enterprise Class Solid State Drive X

2.5" 500GB SATA Class 20 Solid State Drive X

2.5" 256GB SATA Class 20 Solid State Drive X

M.2 PCIe NVMe PCIe SSDs

M.2 1TB PCIe NVMe Class 50 Solid State Drive X

M.2 512GB PCIe NVMe Class 50 Solid State Drive X

M.2 2TB PCIe NVMe Class 40 Solid State Drive X

M.2 1TB PCIe NVMe Class 40 Solid State Drive X

M.2 512GB PCIe NVMe Class 40 Solid State Drive X

M.2 256G PCIe NVMe Class 40 Solid State Drive X

M.2 1TB PCIe NVMe Class 40 SED Solid State Drive X

M.2 512GB PCIe NVMe Class 40 SED Solid State Drive X

U.2 PCIe NVMe PCIe SSDs

U.2 Intel® Optane™ SSD 905P 960GB PCIe NVMe Solid State
Drive

X

U.2 Intel® Optane™ SSD 905P 280GB PCIe NVMe Solid State
Drive

X

DELL™ PRECISION™ 7920 TOWER TECHNICAL GUIDEBOOK

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DELL P R ECI S I O N UL T R A -S P E E D DUO AND Q U A D DRI V E S

DELL™ PRECISION™ 7920 TOWER TECHNICAL GUIDEBOOK

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SYST E M EXP AN S I ON S L O TS

NOTE: See Detailed Engineering Specifications for supported voltage, maximum wattage and card dimensions.

EXTE R N A L PORT S / C ONNE C T ORS

NOTE: See chassis diagrams section for port/connector locations

USB 3.1

Front: 2x USB 3.1 Gen 1 Type A, 2x USB 3.1 Gen 1 Type C

Rear: 6x USB 3.1 Gen1 Type A

Optional: 2 x USB 3.1 Gen 2 Type C on PCIe card

USB 2.0

Internal: 1x USB 2.0 plus

1x 2x5 USB 2.0 header for flex bay. (Requires 3rd party splitter

cable to support 2x USB 2.0 Type A ports)

Serial 1 Rear

Network Connector (RJ-45) 2 Rear

PS/2 2 Rear

Audio:

Universal Audio Jack 1 Front

Audio Line out 1 Rear

Audio Line in/Microphone 1 Rear

PCIe x16 Slot Gen 3

2 Slots - (slots 1-2, 1-4), 2 slots (slots 2-1, 2-2 with 2nd CPU)

4 slots total with 2nd CPU installed

PCIe x16 (wired x8—open ended) 1 (Slot 1)

PCIe x16 Slot (wired x4) 1 (Slot 5)

PCIe x16 Slot (wired x1) 1 Slot 3)

SATA connectors for hard drives and optical drives 8 SATA @6Gb/s plus 1 for optical with Intel controller

All PCIe slots are PCIe Gen 3 and Full height/Full length

DELL™ PRECISION™ 7920 TOWER TECHNICAL GUIDEBOOK

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SYST E M EXP AN S I ON S L O TS A V AIL A B L E WIT H N V IDI A G EFORC E R T X 3 0 8 0 / 3 0 90 G R A P HIC S

NOTE: See Detailed Engineering Specifications for supported voltage, maximum wattage and card dimensions.