Installing System Components 89
System Memory
You can upgrade your system memory to a maximum of 32 GB by installing 533MHz or 667MHz fully
buffered (FB) DDRII memory modules in sets of 256-MB, 512-MB, 1-GB, 2-GB, or 4-GB. The eight
memory sockets are located on the system board under the cooling shroud adjacent to the power supply
bays. See Figure6-2. You can purchase memory upgrade kits from Dell.
NOTICE: If you remove your original memory modules from the system during a memory upgrade, keep them
separate from any new memory modules that you may have, even if you purchased the new memory modules from
Dell. Use only 533 MHz or 667 MHz DDR II FB-DIMMs.
The memory module sockets are divided into two equal branches (0 and 1). Each branch consists of two
channels:
• Channel 0 and channel 1 are in branch 0.
• Channel 2 and channel 3 are in branch 1.
Each channel consists of two DIMM sockets:
• Channel 0 contains DIMM_1, DIMM_5.
• Channel 1 contains DIMM _2, DIMM_6.
• Channel 2 contains DIMM_3, DIMM_7.
• Channel 3 contains DIMM _4, DIMM _8.
The first DIMM socket of each channel has white release tabs.

General Memory Module Installation Guidelines

To ensure optimal performance of your system, observe the following guidelines when configuring your
system memory.
• Use only qualified Fully-Buffered DIMMs (FBDs). FBDs can be either s
ingle-ranked
or d
ual-ranked
.
FBDs m
arked with a 1R are single
-r
anked and modules marked with a 2R are dual
-r
anked.
• A minimum of two identical FBDs must installed.
• DIMM sockets must be populated by lowest number first.
• FBDs m
ust be installed in pairs of matched memory size, speed, and technology
, and the total
number of FBDs in the configuration must total two, four, or eight. For best system performance, all
four, or eight FBDs should be identical memory size, speed, and technology.
•Memory sp
aring and
memory m
irroring require
e
ight FBDs, and all FBDs must be of identical
memory size, speed, and technology.
• Memory sparing and memory mirroring cannot be implemented at the same time.
Book.book Page 89 Friday, February 3, 2006 11:09 AM