System Memory; Overview; Memory Configurations - Asus P5B-VM Manual

1.7

System memory

1.7.1

Overview

The motherboard comes with four Double Data Rate 2 (DDR2) Dual Inline Memory
Modules (DIMM) sockets.
A DDR2 module has the same physical dimensions as a DDR DIMM but has a
240-pin footprint compared to the 184-pin DDR DIMM. DDR2 DIMMs are notched
differently to prevent installation on a DDR DIMM socket.
The figure illustrates the location of the DDR2 DIMM sockets:
Channel
Channel A
Channel B
1.7.2

Memory configurations

You may install 256 MB, 512 MB, 1 GB, and 2 GB unbuffered non-ECC DDR2
DIMMs into the DIMM sockets.
•
•
•
•
•
1-18
Sockets
DIMM_A1 and DIMM_A2
DIMM_B1 and DIMM_B2
You may install varying memory sizes in Channel A and Channel B. The
system maps the total size of the lower-sized channel for the dual-channel
configuration. Any excess memory from the higher-sized channel is then
mapped for single-channel operation.
Always install DIMMs with the same CAS latency. For optimum compatibility,
it is recommended that you obtain memory modules from the same vendor.
If you install four 1 or 2GB memory modules, the system may only recognize
less than 3GB because the address space is reserved for other critical
functions. This limitation appears on Windows
which does not support Physical Address Extension (PAE).
If you install Windows
than 3GB is recommended.
This motherboard does not support memory modules made up of 128 Mb
chips or double sided x16 memory modules.
XP 32-bit operation system, a total memory of less
®
XP 32-bit operation system
®
Chapter 1: Product introduction