Asus M2A74-AM SE - Manual (Page 12)

1.3 Central Processing Unit (CPU)
The motherboard comes with a CPU socket designed for AMD ® AM3 Phenom™ II /
Athlon™ X4 / Athlon™ X3 / Athlon™ X2 processors and AM2+ / AM2 Phenom™ X4 /
Phenom™ X3 / Athlon™ X2 / Athlon™ / Sempron™ processors.
The CPU socket is not compatible with AMD ® Opteron™ processors. Do not install an
Opteron™ processor on this motherboard.
1.4 System memory
1.4.1 Overview
This motherboard comes with two Double Data Rate 2 (DDR2) Dual Inline Memory Modules
(DIMM) sockets. A DDR2 DIMM 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:
• 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 the single-channel operation.
• Always install DIMMs with the same CAS latency. For optimum compatibility, we
recommend that you obtain memory modules from the same vendor.
• Due to the memory address limitation on the 32-bit Windows ® OS, when you install
4GB or more memory on the motherboard, the actual usable memory for the OS can be
about 3GB or less. For effective use of memory, we recommend that you do either of the
following:
- Install a maximum of 3GB system memory if you are using a 32-bit Windows ®
OS.
- Use a 64-bit Windows ® OS if you want to install 4GB or more memory on the
motherboard.
• This motherboard does not support DIMMs made up of 256 megabits (Mb) chips or less.
1.4.2 Memory configurations
You may install 512MB, 1GB, 2GB, and 4GB unbuffered ECC and non-ECC DDR2 DIMMs
into the DIMM sockets.
Channel Sockets
Channel A DIMM_A1
Channel B DIMM_B1
The motherboard supports up to 8GB memory modules on Windows ® XP Professional x64
and Vista x64 editions. You may install a maximum of 4GB DIMMs on each slot.
Chapter 1: Product introduction 1-3