Intel S975XBX2 - Workstation Board Motherboard User manual

October 2006
Order Number: D80929-001
The Intel®Workstation Board S975XBX2 may contain design defects or errors known as errata that may cause the product to deviate from published specifications.
Current characterized errata are documented in the Intel Workstation Board S975XBX2 Specification Update.
Intel® Workstation Board
S975XBX2
Technical Product Specification

Revision History
Revision Revision History Date
-001 First release of the Intel®Workstation Board S975XBX2 Technical Product
Specification
October 2006
This product specification applies to only the standard Intel®Workstation Board S975XBX2 with
BIOS identifier BX97520J.86A.
Changes to this specification will be published in the Intel Workstation Board S975XBX2.
Specification Update before being incorporated into a revision of this document.
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GRANTED BY THIS DOCUMENT. EXCEPT AS PROVIDED IN INTEL’S TERMS AND CONDITIONS OF SALE FOR
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suitability of this product for other PC or embedded non-PC applications or other environments, such as
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or “undefined.” Intel reserves these for future definition and shall have no responsibility whatsoever for
conflicts or incompatibilities arising from future changes to them.
Intel Workstation boards may contain design defects or errors known as errata, which may cause the
product to deviate from published specifications. Current characterized errata are available on request.
Contact your local Intel sales office or your distributor to obtain the latest specifications before placing your
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Copyright ©2006, Intel Corporation. All rights reserved.

iii
Preface
This Technical Product Specification (TPS) specifies the board layout, components,
connectors, power and environmental requirements, and the BIOS for the Intel®
Workstation Board S975XBX2. It describes the standard product and available
manufacturing options.
Intended Audience
The TPS is intended to provide detailed, technical information about the Intel
Workstation Board S975XBX2 and its components to the vendors, system integrators,
and other engineers and technicians who need this level of information. It is
specifically not intended for general audiences.
What This Document Contains
Chapter Description
1 A description of the hardware used on the Workstation Board S975XBX2
2 A map of the resources of the Workstation Board
3 The features supported by the BIOS Setup program
4 A description of the BIOS error messages, beep codes, and POST codes
5 Regulatory compliance and battery disposal information
Typographical Conventions
This section contains information about the conventions used in this specification. Not
all of these symbols and abbreviations appear in all specifications of this type.
Notes, Cautions, and Warnings

NOTE
Notes call attention to important information.
#
INTEGRATOR’S NOTES
Integrator’s notes are used to call attention to information that may be useful to
system integrators.
CAUTION
Cautions are included to help you avoid damaging hardware or losing data.

Intel Workstation Board S975XBX2 Technical Product Specification
iv
Other Common Notation
# Used after a signal name to identify an active-low signal (such as USBP0#)
(NxnX) When used in the description of a component, N indicates component type, xn are the
relative coordinates of its location on the Workstation Board S975XBX2, and X is the
instance of the particular part at that general location. For example, J5J1 is a connector,
located at 5J. It is the first connector in the 5J area.
GB Gigabyte (1,073,741,824 bytes)
GB/sec Gigabytes per second
Gbits/sec Gigabits per second
KB Kilobyte (1024 bytes)
Kbit Kilobit (1024 bits)
kbits/sec 1000 bits per second
MB Megabyte (1,048,576 bytes)
MB/sec Megabytes per second
Mbit Megabit (1,048,576 bits)
Mbits/sec Megabits per second
xxh An address or data value ending with a lowercase h indicates a hexadecimal value.
x.x V Volts. Voltages are DC unless otherwise specified.
* This symbol is used to indicate third-party brands and names that are the property of their
respective owners.

v
Contents
1Product Description
1.1 Overview........................................................................................ 12
1.1.1 Feature Summary ................................................................ 12
1.1.2 Manufacturing Options .......................................................... 13
1.1.3 Board Layout ....................................................................... 14
1.1.4 Block Diagram ..................................................................... 16
1.2 Online Support................................................................................ 17
1.3 Processor ....................................................................................... 17
1.4 System Memory .............................................................................. 18
1.4.1 Memory Configurations ......................................................... 20
1.5 Intel®975X Chipset ......................................................................... 24
1.5.1 USB ................................................................................... 24
1.5.2 IDE Support ........................................................................ 25
1.5.3 Real-Time Clock, CMOS SRAM, and Battery .............................. 26
1.6 Discrete Serial ATA Interface............................................................. 27
1.6.1 Serial ATA Controller............................................................. 27
1.6.2 External Serial ATA Support................................................... 27
1.7 PCI Express Connectors.................................................................... 28
1.8 IEEE-1394a Connectors.................................................................... 29
1.9 Legacy I/O Controller....................................................................... 29
1.9.1 Serial Port ........................................................................... 29
1.9.2 Parallel Port......................................................................... 30
1.9.3 Diskette Drive Controller ....................................................... 30
1.9.4 Keyboard and Mouse Interface ............................................... 30
1.10 Audio Subsystem............................................................................. 31
1.10.1 Audio Subsystem Software .................................................... 31
1.10.2 Audio Connectors ................................................................. 31
1.10.3 6-Channel (5.1) Audio Subsystem........................................... 32
1.11 LAN Subsystem............................................................................... 33
1.11.1 Intel®82573E Gigabit Ethernet Controller ................................ 33
1.11.2 RJ-45 LAN Connector with Integrated LEDs .............................. 33
1.11.3 Alert Standard Format (ASF) Support ...................................... 34
1.11.4 Intel®Active Management Technology..................................... 34
1.11.5 LAN Subsystem Software....................................................... 36
1.12 Hardware Management Subsystem .................................................... 36
1.12.1 Hardware Monitoring and Fan Control ASIC .............................. 36
1.12.2 Thermal Monitoring .............................................................. 37
1.12.3 Fan Monitoring..................................................................... 38
1.12.4 Chassis Intrusion and Detection.............................................. 38

Intel Workstation Board S975XBX2 Technical Product Specification
vi
1.13 Power Management ......................................................................... 38
1.13.1 ACPI................................................................................... 38
1.13.2 Hardware Support ................................................................ 41
1.14 Trusted Platform Module................................................................... 45
2Technical Reference
2.1 Memory Resources .......................................................................... 47
2.1.1 Addressable Memory............................................................. 47
2.1.2 Memory Map........................................................................ 49
2.2 DMA Channels................................................................................. 49
2.3 Fixed I/O Map ................................................................................. 50
2.4 PCI Configuration Space Map ............................................................ 51
2.5 Interrupts ...................................................................................... 52
2.6 PCI Conventional Interrupt Routing Map ............................................. 53
2.7 Connectors..................................................................................... 54
2.7.1 Back Panel Connectors .......................................................... 54
2.7.2 Component-side Connectors and Headers ................................ 56
2.8 Jumper Block .................................................................................. 67
2.9 Mechanical Considerations ................................................................ 68
2.9.1 Form Factor......................................................................... 68
2.9.2 I/O Shield ........................................................................... 69
2.10 Electrical Considerations................................................................... 70
2.10.1 DC Loading.......................................................................... 70
2.10.2 Add-in Board Considerations .................................................. 70
2.10.3 Fan Header Current Capability................................................ 71
2.10.4 Power Supply Considerations ................................................. 71
2.11 Thermal Considerations.................................................................... 72
2.12 Reliability ....................................................................................... 74
2.13 Environmental ................................................................................ 75
3Overview of BIOS Features
3.1 Introduction ................................................................................... 77
3.2 Resource Configuration .................................................................... 78
3.2.1 PCI Autoconfiguration ........................................................... 78
3.2.2 PCI IDE Support................................................................... 78
3.3 System Management BIOS (SMBIOS)................................................. 79
3.4 Watchdog Timer.............................................................................. 79
3.5 Legacy USB Support ........................................................................ 80
3.6 BIOS Updates ................................................................................. 80
3.6.1 Language Support ................................................................ 81
3.6.2 Custom Splash Screen .......................................................... 81

Contents
vii
3.7 Boot Options................................................................................... 81
3.7.1 CD-ROM Boot ...................................................................... 81
3.7.2 Network Boot....................................................................... 81
3.7.3 Booting Without Attached Devices........................................... 82
3.7.4 Changing the Default Boot Device During POST ........................ 82
3.8 BIOS Security Features .................................................................... 83
4Error Messages and Beep Codes
4.1 Speaker ......................................................................................... 85
4.2 BIOS Beep Codes ............................................................................ 85
4.3 BIOS Error Messages ....................................................................... 85
4.4 Port 80h POST Codes ....................................................................... 86
5Regulatory Compliance and Battery Disposal Information
5.1 Regulatory Compliance..................................................................... 91
5.1.1 Safety Regulations................................................................ 91
5.1.2 European Union Declaration of Conformity Statement................ 91
5.1.3 Product Ecology Statements................................................... 93
5.1.4 EMC Regulations .................................................................. 97
5.1.5 Product Certification Markings (Board Level)............................. 98
5.2 Battery Disposal Information............................................................. 99
Figures
1. Workstation Board Components......................................................... 14
2. Block Diagram ................................................................................ 16
3. Memory Channel and DIMM Configuration ........................................... 20
4. Dual Channel (Interleaved) Mode Configuration with Two DIMMs............ 21
5. Dual Channel (Interleaved) Mode Configuration with Three DIMMs ......... 21
6. Dual Channel (Interleaved) Mode Configuration with Four DIMMs ........... 22
7. Single Channel (Asymmetric) Mode Configuration with One DIMM .......... 23
8. Single Channel (Asymmetric) Mode Configuration with Three DIMMs....... 23
9. Location of External Serial ATA-Compatible SATA Port .......................... 27
10. Front/Back Panel Audio Connector Options for 6-Channel (5.1)
Audio Subsystem............................................................................. 32
11. LAN Connector LED Locations............................................................ 33
12. Sensors and Fan Connectors ............................................................. 37
13. Location of the Standby Power Indicator LED....................................... 44
14. Detailed System Memory Address Map ............................................... 48
15. Back Panel Connectors for 6-Channel (5.1) Audio Subsystem................. 55
16. Component-side Connectors and Headers ........................................... 56
17. Connection Diagram for Front Panel Header ........................................ 63
18. Connection Diagram for Front Panel USB Headers ................................ 65
19. Connection Diagram for Front Panel IEEE 1394a Header........................ 66
20. Location of the Jumper Block............................................................. 67
21. Board Dimensions ........................................................................... 68

Intel Workstation Board S975XBX2 Technical Product Specification
viii
22. I/O Shield Dimensions for Boards with the 6-Channel (5.1)
Audio Subsystem............................................................................. 69
23. Localized High Temperature Zones..................................................... 73
Tables
1. Feature Summary............................................................................ 12
2. Manufacturing Options ..................................................................... 13
3. Components Shown in Figure 1 ......................................................... 15
4. Supported Memory Configurations ..................................................... 18
5. Memory Operating Frequencies ......................................................... 19
6. LAN Connector LED States ................................................................ 33
7. Effects of Pressing the Power Switch .................................................. 39
8. Power States and Targeted System Power........................................... 40
9. Wake-up Devices and Events ............................................................ 41
10. System Memory Map ....................................................................... 49
11. DMA Channels................................................................................. 49
12. I/O Map ......................................................................................... 50
13. PCI Configuration Space Map ............................................................ 51
14. Interrupts ...................................................................................... 52
15. PCI Interrupt Routing Map ................................................................ 53
16. Component-side Connectors and Headers Shown in Figure 20................ 57
17. ATAPI CD-ROM Connector (Optional).................................................. 58
18. Front Panel Audio Header ................................................................. 58
19. Front Chassis, Rear Chassis, and MCH Fan Headers .............................. 58
20. Processor Fan and Auxiliary Rear Fan Header ...................................... 58
21. Chassis Intrusion Header.................................................................. 59
22. SCSI Hard Drive Activity LED Header (Optional)................................... 59
23. Serial ATA Connectors...................................................................... 59
24. Main Power Connector...................................................................... 61
25. Processor Core Power Connector (2 x 4 Pin) ........................................ 61
26. Processor Core Power Connector (2 x 2 Pin) ........................................ 61
27. Auxiliary PCI Express Graphics Power ................................................. 61
28. Auxiliary Front Panel Power/Sleep LED Header..................................... 62
29. Front Panel Header .......................................................................... 63
30. States for a One-Color Power LED...................................................... 64
31. States for a Two-Color Power LED...................................................... 64
32. BIOS Setup Configuration Jumper Settings.......................................... 67
33. DC Loading Characteristics ............................................................... 70
34. Fan Header Current Capability........................................................... 71
35. Thermal Considerations for Components ............................................. 74
36. Environmental Specifications............................................................. 75
37. BIOS Setup Program Menu Bar.......................................................... 78
38. BIOS Setup Program Function Keys.................................................... 78
39. Boot Device Menu Options ................................................................ 82
40. Supervisor and User Password Functions............................................. 83
41. Beep Codes .................................................................................... 85

Contents
ix
42. BIOS Error Messages ....................................................................... 85
43. Port 80h POST Code Ranges.............................................................. 86
44. Port 80h POST Codes ....................................................................... 87
45. Typical Port 80h POST Sequence........................................................ 90
46. Safety Regulations........................................................................... 91
47. Lead-Free Board Markings ................................................................ 96
48. EMC Regulations ............................................................................. 97
49. Product Certification Markings ........................................................... 98

Intel Workstation Board S975XBX2 Technical Product Specification
x

11
1Product Description
What This Chapter Contains
1.1 Overview........................................................................................ 12
1.2 Online Support................................................................................ 17
1.3 Processor ....................................................................................... 17
1.4 System Memory .............................................................................. 18
1.5 Intel®975X Chipset ......................................................................... 24
1.6 Discrete Serial ATA Interface............................................................. 27
1.7 PCI Express Connectors.................................................................... 28
1.8 IEEE-1394a Connectors.................................................................... 29
1.9 Legacy I/O Controller....................................................................... 29
1.10 Audio Subsystem............................................................................. 31
1.11 LAN Subsystem............................................................................... 33
1.12 Hardware Management Subsystem .................................................... 36
1.13 Power Management ......................................................................... 38
1.14 Trusted Platform Module................................................................... 45

Intel Workstation Board S975XBX2 Technical Product Specification
12
1.1 Overview
1.1.1 Feature Summary
Table 1 summarizes the major features of the board.
Table 1. Feature Summary
Form Factor ATX (12.00 inches by 9.60 inches [304.80 millimeters by 243.84 millimeters])
Processor •Intel®Core™2 Extreme Processor in an LGA775 socket with a 1066 MHz
system bus
•Intel®Core™2 Duo Processor in an LGA775 socket with a 1066 MHz system
bus
•Intel®Pentium®Processor Extreme Edition in an LGA775 socket with a 1066 or
800 MHz system bus
•Intel®Pentium®4 Processor Extreme Edition in an LGA775 socket with a
1066 MHz system bus
•Intel®Pentium®D Processor in an LGA775 socket with an 800 MHz system bus
•Intel®Pentium®4 Processor in an LGA775 socket with an 800 MHz system bus
Memory •Four 240-pin DDR2 SDRAM Dual Inline Memory Module (DIMM) sockets
•Support for DDR2 800, DDR2 667, and DDR2 533 MHz DIMMs
•Support for up to 8 GB of system memory
•Support for ECC and non-ECC memory
Chipset Intel®975X Chipset, consisting of:
•Intel®82975X Memory Controller Hub (MCH)
•Intel®82801GR I/O Controller Hub (ICH7-R)
Audio Intel®High Definition Audio subsystem
Legacy I/O Control Legacy I/O controller for diskette drive, serial, parallel, and PS/2 ports
USB Support for USB 2.0 devices
Peripheral
Interfaces
•Eight USB ports
•One serial port
•One parallel port
•Four Serial ATA interfaces with RAID support
•One Parallel ATA IDE interface with UDMA 33, ATA-66/100 support
•One diskette drive interface
•PS/2* keyboard and mouse ports
BIOS •Intel®BIOS resident in the SPI Flash device
•Support for Advanced Configuration and Power Interface (ACPI), Plug and Play,
and SMBIOS
•Watchdog timer providing automatic recovery after two failed power-on
self-tests (POSTs)
Instantly Available
PC Technology
•Support for PCI Local Bus Specification Revision 2.2
•Support for PCI Express* Revision 1.0a
•Suspend to RAM support
•Wake on PCI, RS-232, front panel, PS/2 devices, and USB ports
LAN Support Gigabit (10/100/1000 Mbits/sec) LAN subsystem using the Intel®82573E Gigabit
Ethernet Controller
continued

Product Description
13
Table 1. Feature Summary (continued)
Expansion
Capabilities
•Two PCI* Conventional bus add-in card connectors (SMBus routed to both PCI
Conventional bus add-in card connectors)
•One Primary PCI Express x16 (electrical x16 or x8) bus add-in card connector
•One Secondary PCI Express x16 (electrical x8) bus add-in card connector
•One PCI Express x16 (electrical x4) bus add-in card connector
Hardware Monitor
Subsystem
•Hardware monitoring and fan control ASIC
•Voltage sense to detect out of range power supply voltages
•Thermal sense to detect out of range thermal values
•Three fan headers
•Three fan sense inputs used to monitor fan activity
•Fan speed control
•Support for Product Environmental Control Interface (PECI)
1.1.2 Manufacturing Options
Table 2 describes the manufacturing options. Not every manufacturing option is
available in all marketing channels. Please contact your Intel representative to
determine which manufacturing options are available to you.
Table 2. Manufacturing Options
AMT BIOS support for Intel®Active Management Technology (Intel®AMT)
ATAPI CD-ROM
Connector
A 1 x 4-pin ATAPI-style connector for connecting an internal ATAPI CD-ROM drive to
the audio mixer
Audio Subsystem •Intel High Definition Audio subsystem in 6-channel (5.1) audio subsystem with
three analog audio outputs using the Sigmatel 9227 audio codec
Auxiliary PCI
Express Graphics
Power Connector
Provides required additional power when using high power (75 W or greater) add-in
cards in either or both the Secondary PCI Express x16 (electrical x8) and the PCI
Express x16 (electrical x4) bus add-in card connectors
Discrete SATA
RAID Controller
•Marvell* 88SE6145 SATA RAID controller
•Four SATA connectors (in addition to the four SATA connectors on the ICH7-R
SATA interface)
IEEE-1394a
Interface
IEEE-1394a controller and two IEEE-1394a connectors: one back panel connector
and one front-panel header
MCH Fan Header A 3-pin header for powering a fan for the Intel®82975X Memory Controller Hub
(MCH)
Processor Core
Power Connector
One of the following connectors for providing +12 V power to the processor voltage
regulator:
•2 x 4-pin (requires a power supply with a dual-rail 2 x 4 power cable). Boards
equipped with the 2 x 4-pin processor core power connector will also include
heatsinks in the processor voltage regulator area.
•2 x 2-pin
SCSI Hard Drive
LED Header
Allows add-in hard drive controllers (SCSI or other) to use the same LED as the
onboard IDE controller
Trusted Platform
Module (TPM)
A component that enhances platform security

Intel Workstation Board S975XBX2 Technical Product Specification
14
For information about Refer to
Available configurations for the board Section 1.2, page 17
1.1.3 Board Layout
Figure 1 shows the location of the major components.
Figure 1. Workstation Board Components
Table 3 lists the components identified in Figure 1.

Product Description
15
Table 3. Components Shown in Figure 1
Item/callout
from Figure 1 Description
A Auxiliary rear fan header
B PCI Conventional bus add-in card connector 2
C PCI Express x16 (electrical x4) bus add-in card connector
D PCI Conventional bus add-in card connector 1
E Secondary PCI Express x16 (electrical x8) bus add-in card connector
F Front panel audio header
G Intel®82801G I/O Controller Hub (ICH7-R)
H Primary PCI Express x16 (electrical x16 or x8) bus add-in card connector
I Rear chassis fan header
J Auxiliary PCI Express Graphics Power Connector (optional)
K Back panel connectors
L ATAPI CD-ROM connector (optional)
M Processor core power connector
N Memory Controller Hub (MCH) fan header (optional)
O LGA775 processor socket
P Intel 82975X MCH
Q DIMM Channel A sockets [2]
R Processor fan header
S DIMM Channel B sockets [2]
T Main power connector
U Diskette drive connector
V BIOS Setup configuration jumper block
W Chassis intrusion header
X Onboard power button (optional)
Y Battery
Z Parallel ATE IDE connector
AA Serial ATA connectors (ICH7-R) [4]
BB Front chassis fan header
CC Auxiliary front panel power LED header
DD Front panel USB headers [2]
EE IEEE-1394a front panel header
FF Serial ATA RAID connectors (Discrete RAID) (optional) [3]
GG Serial ATA RAID connector compatible with external Serial ATA adapter (red)
HH SCSI Hard Drive Activity LED header (optional)
II Front panel header
JJ Speaker

Intel Workstation Board S975XBX2 Technical Product Specification
16
1.1.4 Block Diagram
Figure 2 is a block diagram of the major functional areas of the board.
Intel 975X Chipset
Intel 82801GR/
82801GH
I/O Controller Hub
(ICH7-R/ICH7-DH)
Intel 82975X
Memory Controller
Hub (MCH)
System Bus
(1066/800 MHz)
LGA775
Processor
Socket
Parallel ATA
IDE Connector
Diskette Drive
Connector
LPC Bus
I/O
Controller PS/2 Keyboard
PS/2 Mouse
Parallel Port
Serial Port
Parallel ATA
IDE Interface
Hardware Monitoring
and Fan Control ASIC
OM18546
Audio
Codec Line Out/Retasking Jack
CD-ROM (Optional)
Primary
PCI Express
x16 Connector
PCI Bus
SMBus
High Definition Audio Link
USB
Dual-Channel
Memory Bus
SMBus
PCI Slot 1
PCI Slot 2
Mic In/Retasking Jack
Line In/Retasking Jack
S/PDIF
SATA IDE
Connectors (4)
SATA IDE
Interface
Channel A
DIMMs (2)
Channel B
DIMMs (2)
Back Panel/Front Panel
USB Ports
Surround Left-Right/Retasking Jack
Center and LFE/Retasking Jack
Front Panel Mic In
Front Panel Line Out
PCI
Bus
TPM Component
(Optional)
LPC Bus
PCI Express x16
(Electrical x4) Slot
LAN
Connector
Gigabit Ethernet
Controller
Serial Peripheral
Interface (SPI)
Flash
Device
SMBus
SATA RAID
Connectors (4)
(Optional)
PCI
Bus
Discrete SATA RAID
Controller
(Optional)
IEEE-1394a Connectors
(Optional)
IEEE-1394a
Controller
(Optional)
LPC
Bus
PCI Express Interface
Secondary
PCI Express
x16 Connector
DMI Interconnect
PCI Express
X16 Interface
SMBus
Figure 2. Block Diagram

Product Description
17
1.2 Online Support
To find information about… Visit this World Wide Web site:
Intel Workstation Board S975XBX2
under “Server Board Products” or
“Server Board Support”
http://www.intel.com/design/motherbd
http://support.intel.com/support/motherboards/desktop
Available configurations for the
Workstation Board S975XBX2
http://developer.intel.com/design/motherbd/bx2/bx2_available.htm
Processor data sheets http://www.intel.com/design/litcentr
ICH7-R/ICH7-DH addressing http://developer.intel.com/design/chipsets/datashts
Custom splash screens http://intel.com/design/motherbd/gen_indx.htm
Audio software and utilities http://www.intel.com/design/motherbd
LAN software and drivers http://www.intel.com/design/motherbd
1.3 Processor
The board is designed to support the following processors:
•Intel Core 2 Extreme Processor in an LGA775 socket with a 1066 MHz system bus
•Intel Core 2 Duo Processor in an LGA775 socket with a 1066 MHz system bus
•Intel Pentium Processor Extreme Edition in an LGA775 socket with a 1066 or
800 MHz system bus
•Intel Pentium 4 Processor Extreme Edition in an LGA775 socket with a 1066 MHz
system bus
•Intel Pentium D Processor in an LGA775 socket with an 800 MHz system bus
•Intel Pentium 4 Processor in an LGA775 socket with an 800 MHz system bus
See the Intel web site listed below for the most up-to-date list of supported processors.
For information about… Refer to:
Supported processors for the board http://www.intel.com/design/motherbd/bx2/bx2_proc.htm
CAUTION
Use only the processors listed on web site above. Use of unsupported processors can
damage the board, the processor, and the power supply.
#
INTEGRATOR’S NOTE
This board has specific requirements for providing power to the processor. Refer to
Section 2.7.2.1 on page 60 for information on power supply requirements for this
board.

Intel Workstation Board S975XBX2 Technical Product Specification
18
1.4 System Memory
The board has four DIMM sockets and supports the following memory features:
•1.8 V and 1.9 V DDR2 SDRAM DIMMs
•Unbuffered, single-sided or double-sided DIMMs with the following restriction:
Double-sided DIMMS with x16 organization are not supported.
•8 GB maximum total system memory. Refer to Section 2.1.1 on page 47 for
information on the total amount of addressable memory.
•Minimum total system memory: 128 MB
•ECC DIMMs and non-ECC DIMMs
•Serial Presence Detect
•DDR2 800, DDR2 667, and DDR2 533 MHz SDRAM DIMMs
NOTES
•Remove the Primary PCI Express x16 (electrical x16 or x8) video card before
installing or upgrading memory to avoid interference with the memory retention
mechanism.
•To be fully compliant with all applicable DDR SDRAM memory specifications, the
board should be populated with DIMMs that support the Serial Presence Detect
(SPD) data structure. This allows the BIOS to read the SPD data and program the
chipset to accurately configure memory settings for optimum performance. If non-
SPD memory is installed, the BIOS will attempt to correctly configure the memory
settings, but performance and reliability may be impacted or the DIMMs may not
function under the determined frequency.
Table 4 lists the supported DIMM configurations.
Table 4. Supported Memory Configurations
DIMM
Capacity
Configuration
(Note 1)
SDRAM
Density
SDRAM Organization
Front-side/Back-side
Number of SDRAM
Devices (Note 2)
128 MB SS 256 Mbit 16 M x 16/empty 4 [5]
256 MB SS 256 Mbit 32 M x 8/empty 8 [9]
256 MB SS 512 Mbit 32 M x 16/empty 4 [5]
512 MB DS 256 Mbit 32 M x 8/32 M x 8 16 [18]
512 MB SS 512 Mbit 64 M x 8/empty 8 [9]
512 MB SS 1 Gbit 64 M x 16/empty 4 [5]
1024 MB DS 512 Mbit 64 M x 8/64 M x 8 16 [18]
1024 MB SS 1 Gbit 128 M x 8/empty 8 [9]
2048 MB DS 1 Gbit 128 M x 8/128 M x 8 16 [18]
Notes:
1. In the second column, “DS” refers to double-sided memory modules (containing two rows of SDRAM)
and “SS” refers to single-sided memory modules (containing one row of SDRAM).
2. In the fifth column, the number in brackets specifies the number of SDRAM devices on an ECC DIMM.

Product Description
19
#
INTEGRATOR’S NOTE
Refer to Section 2.1.1, on page 47 for additional information on available memory.

NOTE
Regardless of the DIMM type used, the memory frequency will either be equal to or
less than the processor system bus frequency. For example, if DDR2 800 memory
is used with a 533 MHz system bus frequency processor, the memory will operate
at 533 MHz. Table 5 lists the resulting operating memory frequencies based on the
combination of DIMMs and processors.
Table 5. Memory Operating Frequencies
DIMM Type Processor System Bus Frequency Resulting Memory Frequency
DDR2 533 800 MHz 533 MHz
DDR2 533 1066 MHz 533 MHz
DDR2 667 800 MHz 667 MHz
DDR2 667 1066 MHz 667 MHz
DDR2 800 800 MHz 800 MHz
DDR2 800 1066 MHz 800 MHz

Intel Workstation Board S975XBX2 Technical Product Specification
20
1.4.1 Memory Configurations
The Intel 82975X MCH supports two types of memory organization:
•Dual channel (Interleaved) mode. This mode offers the highest throughput for
real world applications. Dual channel mode is enabled when the installed memory
capacities of both DIMM channels are equal. Technology and device width can vary
from one channel to the other but the installed memory capacity for each channel
must be equal. If different speed DIMMs are used between channels, the slowest
memory timing will be used.
•Single channel (Asymmetric) mode. This mode is equivalent to single channel
bandwidth operation for real world applications. This mode is used when only a
single DIMM is installed or the memory capacities are unequal. Technology and
device width can vary from one channel to the other. If different speed DIMMs are
used between channels, the slowest memory timing will be used.
Figure 3 illustrates the memory channel and DIMM configuration.

NOTE
The DIMM0 sockets of both channels are blue. The DIMM1 sockets of both channels
are black.
OM18526
Channel A, DIMM 0
Channel A, DIMM 1
Channel B, DIMM 0
Channel B, DIMM 1
Figure 3. Memory Channel and DIMM Configuration