Asus P7P55 LX User Manual

P7P55 LX

Motherboard

E5015

First Edition V1

September 2009

Copyright © 2009 ASUSTeK Computer Inc. All Rights Reserved.

No part of this manual, including the products and software described in it, may be reproduced,
transmitted, transcribed, stored in a retrieval system, or translated into any language in any form or by any
means, except documentation kept by the purchaser for backup purposes, without the express written
permission of ASUSTeK Computer Inc. (“ASUS”).

Product warranty or service will not be extended if: (1) the product is repaired, modied or altered, unless
such repair, modication of alteration is authorized in writing by ASUS; or (2) the serial number of the

product is defaced or missing.

ASUS PROVIDES THIS MANUAL “AS IS” WITHOUT WARRANTY OF ANY KIND, EITHER EXPRESS
OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE IMPLIED WARRANTIES OR CONDITIONS OF
MERCHANTABILITY OR FITNESS FOR A PARTICULAR PURPOSE. IN NO EVENT SHALL ASUS, ITS
DIRECTORS, OFFICERS, EMPLOYEES OR AGENTS BE LIABLE FOR ANY INDIRECT, SPECIAL,
INCIDENTAL, OR CONSEQUENTIAL DAMAGES (INCLUDING DAMAGES FOR LOSS OF PROFITS,
LOSS OF BUSINESS, LOSS OF USE OR DATA, INTERRUPTION OF BUSINESS AND THE LIKE),
EVEN IF ASUS HAS BEEN ADVISED OF THE POSSIBILITY OF SUCH DAMAGES ARISING FROM ANY
DEFECT OR ERROR IN THIS MANUAL OR PRODUCT.

SPECIFICATIONS AND INFORMATION CONTAINED IN THIS MANUAL ARE FURNISHED FOR
INFORMATIONAL USE ONLY, AND ARE SUBJECT TO CHANGE AT ANY TIME WITHOUT NOTICE,
AND SHOULD NOT BE CONSTRUED AS A COMMITMENT BY ASUS. ASUS ASSUMES NO
RESPONSIBILITY OR LIABILITY FOR ANY ERRORS OR INACCURACIES THAT MAY APPEAR IN THIS
MANUAL, INCLUDING THE PRODUCTS AND SOFTWARE DESCRIBED IN IT.

Products and corporate names appearing in this manual may or may not be registered trademarks or

copyrights of their respective companies, and are used only for identication or explanation and to the
owners’ benet, without intent to infringe.

ii

Contents

Notices ......................................................................................................... vi

Safety information ..................................................................................... vii

About this guide ....................................................................................... viii

P7P55 LX specications summary ............................................................ x

Chapter 1: Product introduction

1.1 Welcome! ...................................................................................... 1-1

1.2 Package contents .........................................................................

1.3 Special features ............................................................................

1.3.1 Product highlights ...........................................................

1.3.2 Innovative ASUS features ...............................................

1.4 Before you proceed .....................................................................

1.5 Motherboard overview .................................................................

1.5.1 Placement direction ........................................................

1.5.2 Screw holes ....................................................................

1.5.3 Motherboard layout .........................................................

1.5.4 Layout contents ...............................................................

1.6 Central Processing Unit (CPU) ...................................................

1.6.1 Installing the CPU ...........................................................

1.6.2 Installing the CPU heatsink and fan ...............................

1.6.3 Uninstalling the CPU heatsink and fan .........................

1.7 System memory .........................................................................

1.7.1 Overview .......................................................................

1.7.2 Memory congurations ..................................................

1.7.3 Installing a DIMM ..........................................................

1.7.4 Removing a DIMM ........................................................

1.8 Expansion slots ..........................................................................

1.8.1 Installing an expansion card .........................................

1.8.2 Conguring an expansion card .....................................

1.8.3 PCI slots ........................................................................

1.8.4 PCI Express x1 slots .....................................................

1.8.5 PCI Express x16 slots ...................................................

1.9 Jumpers ......................................................................................

1.10 MemOK! switch ..........................................................................

1-1

1-1

1-1

1-2

1-5

1-6

1-6

1-6

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1-8

1-8

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1-14

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iii

Contents

1.11 Connectors ................................................................................. 1-23

1.11.1 Rear panel connectors ..................................................

1.11.2 Internal connectors .......................................................

1.12 Software support ........................................................................

1.12.1 Installing an operating system ......................................

1.12.2 Support DVD information ..............................................

Chapter 2: BIOS information

2.1 Managing and updating your BIOS ............................................ 2-1

2.1.1 ASUS Update utility ........................................................

2.1.2 ASUS EZ Flash 2 ............................................................

2.1.3 ASUS CrashFree BIOS ...................................................

2.1.4 ASUS BIOS Updater .......................................................

2.2 BIOS setup program ....................................................................

2.2.1 BIOS menu screen ..........................................................

2.2.2 Menu bar .........................................................................

2.2.3 Navigation keys ...............................................................

2.2.4 Menu items .....................................................................

2.2.5 Submenu items ...............................................................

2.2.6 Conguration elds .........................................................

2.2.7 Pop-up window ...............................................................

2.2.8 Scroll bar .........................................................................

2.2.9 General help ...................................................................

2.3 Main menu ....................................................................................

2.3.1 System Time ...................................................................

2.3.2 System Date ...................................................................

2.3.3 SATA1~6 .........................................................................

2.3.4 Storage Conguration ...................................................

2.3.5 AHCI Conguration ........................................................

2.3.6 System Information ........................................................

2.4 Ai Tweaker menu ........................................................................

2.4.1 Ai Overclock Tuner ........................................................

2.4.2 CPU Ratio Setting .........................................................

2.4.3 Intel(R) SpeedStep(TM) Tech .......................................

2.4.4 Intel(R) TurboMode Tech

............................................... 2-13

1-23

1-24

1-30

1-30

1-30

2-1

2-2

2-3

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2-6

2-7

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iv

Contents

2.4.5 Xtreme Phase Full Power Mode ................................... 2-13

2.4.6 DRAM Frequency .........................................................

2.4.7 QPI Frequency ..............................................................

2.4.8. DRAM Timing Control ...................................................

2.4.9 CPU Clock Skew ...........................................................

2.4.10 VCore Over Voltage ......................................................

2.4.11 IMC Voltage ..................................................................

2.4.12 CPU PLL Voltage ..........................................................

2.4.13 PCH Voltage .................................................................

2.4.14 DRAM Voltage ..............................................................

2.4.15 Load-Line Calibration ....................................................

2.5 Advanced menu .........................................................................

2.5.1 CPU Conguration ........................................................

2.5.2 North Bridge Conguration ...........................................

2.5.3 Onboard Devices Conguration ....................................

2.5.4 USB Conguration ........................................................

2.5.5 PCIPnP .........................................................................

2.5.6 Intel VT-d .......................................................................

2.6 Power menu ................................................................................

2.6.1 Suspend Mode ..............................................................

2.6.2 ACPI 2.0 Support ..........................................................

2.6.3 ACPI APIC Support .......................................................

2.6.4 APM Conguration ........................................................

2.6.5 Hardware Monitor .........................................................

2.7 Boot menu ..................................................................................

2.7.1 Boot Device Priority ......................................................

2.7.2 Boot Settings Conguration ..........................................

2.7.3 Security .........................................................................

2.8 Tools menu .................................................................................

2.8.1 ASUS O.C. Prole .........................................................

2.8.2 AI NET 2

2.8.3 Express Gate ................................................................

2.8.4 ASUS EZ Flash 2 ..........................................................

2.9 Exit menu ....................................................................................

........................................................................ 2-27

2-14

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v

Notices

Federal Communications Commission Statement

This device complies with Part 15 of the FCC Rules. Operation is subject to the following two
conditions:

• This device may not cause harmful interference, and

• This device must accept any interference received including interference that may cause
undesired operation.

This equipment has been tested and found to comply with the limits for a Class B digital

device, pursuant to Part 15 of the FCC Rules. These limits are designed to provide
reasonable protection against harmful interference in a residential installation. This

equipment generates, uses and can radiate radio frequency energy and, if not installed

and used in accordance with manufacturer’s instructions, may cause harmful interference
to radio communications. However, there is no guarantee that interference will not occur

in a particular installation. If this equipment does cause harmful interference to radio or
television reception, which can be determined by turning the equipment off and on, the user

is encouraged to try to correct the interference by one or more of the following measures:

•

Reorient or relocate the receiving antenna.

•

Increase the separation between the equipment and receiver.

•

Connect the equipment to an outlet on a circuit different from that to which the receiver is

connected.

•

Consult the dealer or an experienced radio/TV technician for help.

The use of shielded cables for connection of the monitor to the graphics card is required
to assure compliance with FCC regulations. Changes or modications to this unit not

expressly approved by the party responsible for compliance could void the user’s authority

to operate this equipment.

Canadian Department of Communications Statement

This digital apparatus does not exceed the Class B limits for radio noise emissions from
digital apparatus set out in the Radio Interference Regulations of the Canadian Department
of Communications.

This class B digital apparatus complies with Canadian ICES-003.

REACH

Complying with the REACH (Registration, Evaluation, Authorisation, and Restriction of
Chemicals) regulatory framework, we published the chemical substances in our products at
ASUS REACH website at http://green.asus.com/english/REACH.htm.

DO NOT throw the motherboard in municipal waste. This product has been designed to
enable proper reuse of parts and recycling. This symbol of the crossed out wheeled bin

indicates that the product (electrical and electronic equipment) should not be placed in

municipal waste. Check local regulations for disposal of electronic products.

DO NOT throw the mercury-containing button cell battery in municipal waste. This symbol
of the crossed out wheeled bin indicates that the battery should not be placed in municipal
waste.

vi

Safety information

Electrical safety

•

To prevent electric shock hazard, disconnect the power cable from the electric outlet

before relocating the system.

•

When adding or removing devices to or from the system, ensure that the power cables
for the devices are unplugged before the signal cables are connected. If possible,
disconnect all power cables from the existing system before you add a device.

•

Before connecting or removing signal cables from the motherboard, ensure that all
power cables are unplugged.

•

Seek professional assistance before using an adapter or extension cord. These devices
could interrupt the grounding circuit.

•

Ensure that your power supply is set to the correct voltage in your area. If you are not
sure about the voltage of the electrical outlet you are using, contact your local power
company.

•

If the power supply is broken, do not try to x it by yourself. Contact a qualied service

technician or your retailer.

• The optical S/PDIF is an optional component (may or may not be included in your

motherboard) and is dened as a CLASS 1 LASER PRODUCT.

INVISIBLE LASER RADIATION, AVOID EXPOSURE TO BEAM.

• Never dispose of the battery in re. It could explode and release harmful substances into

the environment.

• Never dispose of the battery with your regular household waste. Take it to a hazardous

material collection point.

• Never replace the battery with an incorrect battery type.

• RISK OF EXPLOSION IF BATTERY IS REPLACED BY AN INCORRECT TYPE.

• DISPOSE OF USED BATTERIES ACCORDING TO THE ABOVE BATTERY-RELATED
INSTRUCTIONS.

vii

Operation safety

•

Before installing the motherboard and adding devices on it, carefully read all the manuals
that came with the package.

•

Before using the product, ensure that all cables are correctly connected and the power
cables are not damaged. If you detect any damage, contact your dealer immediately.

•

To avoid short circuits, keep paper clips, screws, and staples away from connectors,
slots, sockets and circuitry.

• Avoid dust, humidity, and temperature extremes. Do not place the product in any area
where it may become wet.

This motherboard should only be used in environments with ambient temperatures between
5ºC (41ºF) and 40ºC (104ºF).

• Place the product on a stable surface.

• If you encounter technical problems with the product, contact a qualied service

technician or your retailer.

About this guide

This user guide contains the information you need when installing and conguring the

motherboard.

How this guide is organized

This guide contains the following parts:

•

Chapter 1: Product introduction

This chapter describes the features of the motherboard and the new technology it

supports.

• Chapter 2: BIOS information

This chapter tells how to change system settings through the BIOS Setup menus.

Detailed descriptions of the BIOS parameters are also provided.

viii

Conventions used in this guide

To ensure that you perform certain tasks properly, take note of the following symbols used
throughout this manual.

DANGER/WARNING: Information to prevent injury to yourself when trying to

complete a task.

CAUTION: Information to prevent damage to the components when trying to

complete a task.

IMPORTANT: Instructions that you MUST follow to complete a task.

NOTE: Tips and additional information to help you complete a task.

Where to nd more information

Refer to the following sources for additional information and for product and software
updates.

1. ASUS websites

The ASUS website provides updated information on ASUS hardware and software

products. Refer to the ASUS contact information.

2. Optional documentation

Your product package may include optional documentation, such as warranty yers,

that may have been added by your dealer. These documents are not part of the
standard package.

Typography

Bold text Indicates a menu or an item to select.

Italics

Used to emphasize a word or a phrase.

<Key> Keys enclosed in the less-than and greater-than sign means
that you must press the enclosed key.
Example: <Enter> means that you must press the Enter or
Return key.

<Key1>+<Key2>+<Key3> If you must press two or more keys simultaneously, the key

names are linked with a plus sign (+).
Example: <Ctrl>+<Alt>+<D>

ix

P7P55 LX specications summary

CPU LGA1156 socket for Intel® Core™ i7/ Core™ i5 processors

Chipset Intel® P55 Express Chipset

Memory Dual-channel memory architecture

Expansion slots 1 x PCI Express™ 2.0 x16 slot (single at x16)

Multi-GPU Support Supports ATI® Quad-GPU CrossFireX™ technology

Storage Intel® P55 Express Chipset:

LAN Realtek® RTL8112L Gigabit LAN controller featuring AI NET2

Audio VIA® VT1708S 8-channel High Denition Audio CODEC

USB Supports up to 14 USB 2.0/1.1 ports (6 ports at mid-board,

Supports Intel® Turbo Boost Technology
* Refer to www.asus.com for Intel® CPU support list.

4 x 240-pin DIMM slots support maximum 16GB unbuffered
non-ECC DDR3 2200(O.C.) / 1600 / 1333 / 1066MHz

memory modules
* Supports Intel® Extreme Memory Prole (XMP)
** Hyper DIMM support is subject to the physical
characteristics of individual CPUs.
*** Refer to www.asus.com for the latest Memory QVL
(Qualied Vendors List).
**** When you install a total memory of 4GB or more,
Windows® 32-bit operating system may only recognize less
than 3GB. We recommend a maximum of 3GB system
memory if you are using a Windows® 32-bit operating
system.

1 x PCI Express™ 2.0 x16 slot (at x4 mode, 2.5GT/s)
2 x PCI Express™ 2.0 x1 slots (2.5GT/s)

3 x PCI slots

- 6 x SATA 3.0 Gb/s ports

- Intel® Matrix Storage supporting SATA RAID 0,1, 5,
and 10

VIA® VT6415 PATA controller:

- 1 x Ultra DMA 133/100/66 for up to 2 PATA devices

- Optical S/PDIF out port at back I/O

- Supports Jack-detection and Multi-streaming

- ASUS Noise Filter

8 ports at the back panel)

(continued on the next page)

x

P7P55 LX specications summary

ASUS unique features ASUS Exclusive Overclocking Features:

ASUS exclusive
overclocking features

Back panel I/O ports 1 x PS/2 keyboard port (Purple)

- ASUS TurboV

- ASUS Turbo Key
ASUS Exclusive Features:

- MemOK!

- ASUS EPU

- Express Gate
ASUS Quiet Thermal Solution:

- ASUS Fanless Design: Stylish Heatsink Solution

- ASUS Fan Xpert

ASUS EZ DIY:

- ASUS Q-DIMM

- ASUS O.C. Prole

- ASUS CrashFree BIOS 3

- ASUS EZ Flash 2

- ASUS My Logo 2

- Multi-language BIOS

Precision Tweaker 2:

- vCore: Adjustable CPU voltage at 0.00625V increment

- vIMC: Adjustable IMC voltage at 0.05V increment

- vDRAM Bus: 11-step DRAM voltage control

- vPCH: 2-step chipset voltage control

- vCPU PLL: 4-step reference voltage control

SFS (Stepless Frequency Selection):

- Internal Base Clock tuning from 80 MHz up to 500 MHz
at 1MHz increment

- PCI Express frequency tuning from 100MHz up to
150MHz at 1MHz increment

Overclocking Protection:

- ASUS C.P.R.(CPU Parameter Recall)

1 x PS/2 mouse port (Green)
1 x S/PDIF Out port (Optical)
1 x LAN (RJ-45) port
8 x USB 2.0/1.1 ports
8-channel audio I/O ports

(continued on the next page)

xi

P7P55 LX specications summary

Internal I/O
connectors

BIOS 16 Mb Flash ROM, AMI BIOS, PnP, DMI 2.0, WfM 2.0,

Manageability WfM 2.0, DMI 2.0, WOL by PME, WOR by PME, PXE

Accessories 1 x Ultra DMA 133/100/66 cable

Support DVD Drivers

Form factor ATX form factor: 12 in x 8.6 in (30.5 cm x 21.8 cm)

3 x USB 2.0/1.1 connectors support additional 6 USB 2.0/1.1
ports
1 x IDE connector
6 x SATA connectors
1 x CPU fan connector
1 x Chassis fan connector
1 x Power fan connector
1 x Front panel audio connector
1 x S/PDIF Out header
1 x CD audio in connector

1 x 24-pin EATX power connector
1 x 4-pin ATX 12V power connector

1 x System panel connector
1 x MemOK! button
1 x COM connector

SM BIOS 2.5, ACPI 2.0a, Multi-language BIOS,
ASUS EZ Flash 2, ASUS CrashFree BIOS 3

2 x Serial ATA 3.0Gb/s cables

1 x I/O shield
1 x User Manual

ASUS Utilities
ASUS Update
Anti-virus software (OEM version)

* Specications are subject to change without notice.

xii

Chapter 1

Product introduction

1.1 Welcome!

Thank you for buying an ASUS® P7P55 LX motherboard!
The motherboard delivers a host of new features and latest technologies, making it another

standout in the long line of ASUS quality motherboards!

Before you start installing the motherboard, and hardware devices on it, check the items in
your package with the list below.

1.2 Package contents

Check your motherboard package for the following items.

Motherboard ASUS P7P55 LX motherboard

Cables 2 x Serial ATA 3.0Gb/s cables

1 x Ultra DMA 133/100/66 cable

Accessories 1 x I/O shield

Application DVD ASUS motherboard support DVD

Documentation User Manual

If any of the above items is damaged or missing, contact your retailer.

1.3 Special features

1.3.1 Product highlights

ASUS P7P55 LX 1-1

Intel® LGA1156 Lynneld Processor Ready

This motherboard supports the latest Intel® Lynneld processors in
LGA1156 package, which has memory and PCI Express controller

integrated to support 2-channel (4 DIMMs) DDR3 memory and 16 PCI
Express 2.0 lanes, providing great graphics performance. Intel® Lynneld
processor is one of the most powerful and energy efcient CPU in the

world.

Intel® P55

The Intel® P55 Express Chipset is the latest one-chipset design to
support the latest 1156 socket Intel® Core™ i7 / Core™ i5 processors.
Intel® P55 provides improved performance by utilizing serial point-to-point
links, allowing increased bandwidth and stability.

ATI® Quad-GPU CrossFireX™ support

P7P55 LX brings you the ATI® Quad-GPU CrossFireX™ support. The
motherboard features the most powerful Intel® P55 platform to optimize

PCIe allocation in multiple GPU congurations. Expect a brand-new

gaming style you’ve never experienced before!

Dual-Channel DDR3 2200(O.C.) / 1600 / 1333 / 1066 support

The motherboard supports DDR3 memory that features data transfer

rates of 2200(O.C.) / 1600 / 1333 / 1066 MHz to meet the higher
bandwidth requirements of the latest 3D graphics, multimedia, and

Internet applications. The dual-channel DDR3 architecture enlarges the
bandwidth of your system memory to boost system performance.

Serial ATA 3Gb/s technology and RAID support

This motherboard supports hard drives based on the Serial ATA (SATA)

3Gb/s storage specications, delivering enhanced salability and doubling

the bus bandwidth for high-speed data saving and retrieval. It also

supports RAID 0, RAID 1, RAID 5 and RAID 10 congurations for Serial

ATA hard drives.

S/PDIF digital sound ready

This motherboard provides convenient connectivity to external home
theater audio systems via the S/PDIF-out (SONY-PHILIPS Digital
Interface) jack. It allows digital audio transfer and keeps the best signal

quality.

Gigabit LAN solution

The onboard LAN controller is a highly integrated Gb LAN controller. It is

enhanced with an ACPI management function to provide efcient power

management for advanced operating systems.

1.3.2 Innovative ASUS features

Turbo Key

ASUS Turbo Key allows you to turn the PC power button into a physical
overclocking button. After the easy setup, Turbo Key can boost
performances without interrupting ongoing work or games—with just one
touch!

1-2 Chapter 1: Product introduction

ASUS TurboV

Feel the adrenaline rush of real-time OC-now a reality with the ASUS
TurboV. This easy OC tool allows you to overclock without exiting or

rebooting the OS; and its user-friendly interface makes overclock with just
a few clicks away. Moreover, the ASUS OC proles in TurboV provides

the best O.C. settings in different scenarios.

MemOK!

Memory compatibility is among the top concerns during computer
upgrades. Worry no more. MemOK! is the fastest memory booting

solution today. This remarkable memory rescue tool requires nothing but

a push of a button to patch memory issues and get your system up and
running in no time. The technology is able to determine failsafe settings
that can dramatically improve your system booting success.

ASUS EPU

ASUS EPU is a unique power saving technology that detects the current

system loadings and adjusts the power consumption in real time.

ASUS Express Gate

Express Gate is an ASUS exclusive OS, which lets you instantly access
the Internet and key applications before entering the Windows® OS.

• ASUS Express Gate supports installation on SATA HDDs, USB HDDs and ash
drives with at least 1.2GB free disk space. When installing it on USB HDDs or
ash drives, connect the drives to the motherboard USB port before turning on the

computer.

• The actual boot time depends on the system conguration.

• ASUS Express Gate supports le uploading from SATA HDDs, ODDs and USB
drives. It supports le downloading to USB drives only.

• ASUS Express Gate complies with the OpenGL standard. Refer to
for Express Gate source codes.

support.asus.com

ASUS Fan Xpert

ASUS Fan Xpert intelligently allows you to adjust both the CPU and
chassis fan speeds according to different ambient temperatures caused
by different climate conditions in different geographic regions and your

PC’s loading. The built-in variety of useful proles offer exible controls of
fan speed to achieve a quiet and cool environment.

ASUS O.C. Prole

The motherboard features the ASUS O.C. Prole that allows you to

conveniently store or load multiple BIOS settings. The BIOS settings can

be stored in the CMOS or a separate le, giving you the freedom to share

and distribute your favorite settings.

ASUS P7P55 LX 1-3

ASUS MyLogo2™

This feature allows you to convert your favorite photo into a 256-color

boot logo for a more colorful and vivid image on your screen.

ASUS CrashFree BIOS 3

ASUS CrashFree BIOS 3 is an auto-recovery tool that allows you to

restore a corrupted BIOS le using the bundled support DVD or USB
ash disk that contains the latest BIOS le.

ASUS EZ Flash 2

ASUS EZ Flash 2 is a utility that allows you to update the BIOS without

using an OS-based utility.

ASUS AI NET2

ASUS AI NET2 remotely detects the cable connection immediately after

turning on the system, and any faulty cable connections are reported
back up to 100 meters at 1 meter accuracy.

C.P.R. (CPU Parameter Recall)

The BIOS C.P.R. feature automatically restores the CPU default settings
when the system hangs due to overclocking failure. C.P.R. eliminates the
need to open the system chassis and clear the RTC data. Simply shut
down and reboot the system, and the BIOS automatically restores the
CPU parameters to their default settings.

Green ASUS

This motherboard and its packaging comply with the European Union’s

Restriction on the use of Hazardous Substances (RoHS). This is in line

with the ASUS vision of creating environment-friendly and recyclable

products/packaging to safeguard consumers’ health while minimizing the

impact on the environment.

1-4 Chapter 1: Product introduction

1.4 Before you proceed

P7P55 LX

P7P55 LX Onboard LED

SB_PWR

ON

Standby Power Powered Off

OFF

Take note of the following precautions before you install motherboard components or change
any motherboard settings.

• Unplug the power cord from the wall socket before touching any component.

• Before handling components, use a grounded wrist strap or touch a safely grounded
object or a metal object, such as the power supply case, to avoid damaging them due to
static electricity.

• Hold components by the edges to avoid touching the ICs on them.

• Whenever you uninstall any component, place it on a grounded antistatic pad or in the
bag that came with the component.

• Before you install or remove any component, ensure that the ATX power supply is
switched off or the power cord is detached from the power supply. Failure to do so may
cause severe damage to the motherboard, peripherals, or components.

Onboard LED

The motherboard comes with a standby power LED that lights up to indicate that the system
is ON, in sleep mode, or in soft-off mode. This is a reminder that you must shut down
the system and unplug the power cable before removing or plugging in any motherboard
component. The illustration below shows the location of the onboard LED.

ASUS P7P55 LX 1-5

1.5 Motherboard overview

P7P55 LX

Before you install the motherboard, study the conguration of your chassis to ensure that the
motherboard ts into it.

Ensure that you unplug the power cord before installing or removing the motherboard.
Failure to do so can cause you physical injury and damage motherboard components.

1.5.1 Placement direction

When installing the motherboard, ensure that you place it into the chassis in the correct
orientation. The edge with external ports goes to the rear part of the chassis as indicated in
the image below.

1.5.2 Screw holes

Place six screws into the holes indicated by circles to secure the motherboard to the chassis.

Do not overtighten the screws! Doing so can damage the motherboard.

Place this side towards
the rear of the chassis

1-6 Chapter 1: Product introduction

1.5.3 Motherboard layout

21.8cm(8.6in)

30.5cm(12.0in)

USB56

USB34

SPDIF_O

KBPWR

ATX12V

USBPW1-8

ICS

9LRS954

VIA

VT1708S

P7P55 LX

16Mb
BIOS

USBPW9-14

VIA

VT6415

9

10

11

1.5.4 Layout contents

Connectors/Jumpers/Slots/LED Page Connectors/Jumpers/Slots/LED Page

1. Keyboard power (3-pin KBPWR) 1-21 9. Serial ATA connectors (7-pin SATA1-6) 1-28

2. ATX power connectors (24-pin EATXPWR, 4-pin
ATX12V)

3. USB device wake-up (3-pin USBPW1-8, 3-pin

USBPW9-14)

4. CPU, power, and chassis fan connectors (4-pin
CPU_FAN, 3-pin PWR_FAN, 3-pin CHA_FAN)

5. LGA1156 CPU socket 1-8 13. Digital audio connector (4-1 pin

6. DDR3 DIMM slots 1-13 14. Optical drive audio connector (4-pin CD) 1-25

7. IDE connector (40-1 pin PRI_EIDE) 1-25 15. Front panel audio connector (10-1 pin

1-26 10. Clear RTC RAM (3-pin CLRTC) 1-20

1-21 11. System panel connector (20-8 pin PANEL) 1-29

1-27 12. USB connectors (10-1 pin USB910,

USB1112, USB1314)

SPDIF_OUT)

AAFP)

8. Onboard LED (SB_PWR) 1-5 16. Serial port connector (10-1 pin COM1) 1-28

ASUS P7P55 LX 1-7

1-26

1-27

1-24

1.6 Central Processing Unit (CPU)

A

B

P7P55 LX

P7P55 LX socket LGA1156

The motherboard comes with a surface mount LGA1156 socket designed for the Intel®
Core™ i7 / Core™ i5 processors.

Unplug all power cables before installing the CPU.

• Upon purchase of the motherboard, ensure that the PnP cap is on the socket and the
socket contacts are not bent. Contact your retailer immediately if the PnP cap is missing,
or if you see any damage to the PnP cap/socket contacts/motherboard components.
ASUS will shoulder the cost of repair only if the damage is shipment/transit-related.

• Keep the cap after installing the motherboard. ASUS will process Return Merchandise

Authorization (RMA) requests only if the motherboard comes with the cap on the

LGA1156 socket.

• The product warranty does not cover damage to the socket contacts resulting from
incorrect CPU installation/removal, or misplacement/loss/incorrect removal of the PnP
cap.

1.6.1 Installing the CPU

To install a CPU:

1. Locate the CPU socket on the motherboard.

2. Press the load lever with your thumb (A),

and then move it to the right (B) until it is

Load lever

released from the retention tab.

To prevent damage to the socket pins,
do not remove the PnP cap unless
you are installing a CPU.

Retention tab

1-8 Chapter 1: Product introduction

3. Lift the load lever in the direction of the
arrow until the load plate is completely
lifted.

4. Remove the PnP cap from the CPU
socket.

Load plate

PnP cap

5. Position the CPU over the socket,
ensuring that the gold triangle is on the
bottom-left corner of the socket, and

then t the socket alignment keys into

CPU notches

the CPU notches.

The CPU ts in only one correct

orientation. DO NOT force the CPU
into the socket to prevent bending
the connectors on the socket and
damaging the CPU!

ASUS P7P55 LX 1-9

Gold

triangle

mark

Alignment keys