Asus P5QL-EM User Manual

Page 22

1-12

Chapter 1: Product introduction

1.7.2

Memory configurations

You may install 256MB, 512MB, 1GB and 2GB unbuffered non-ECC DDR2 DIMMs into the

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 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.

• Due to the memory address limitation on 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 install a 64-bit

Windows OS when having 4GB or more memory installed on the motherboard.

• Due to chipset limitation, this motherboard only supports up to the total of four ranks (four

sides in total) of RAM at max.

• This motherboard does not support DIMMs made up of 256 megabit (Mb) chips or less.

Mode

DIMM_A1

DIMM_A2

DIMM_B1

DIMM_B2

One DIMM

DS/SS

Two DIMMs

DS/SS

Three DIMMs

DS/SS

Four DIMMs

• When using only one memory module, start installing the DDR2 DIMM from slot

DIMM_A1 or DIMM_B1 for better overclocking capability.

• For dual-channel configuration, you may:
-

install identical DIMMs in all four sockets OR

install identical DIMM pair in DIMM_A1 and DIMM_B1 (yellow sockets) and

another identical DIMM pair in DIMM_A2 and DIMM_B2 (black sockets)

• Always use identical DDR2 DIMM pairs for dual channel mode. For optimum

compatibility, we recommend that you obtain memory modules from the same vendor.