Asus P5K/EPU manual Memory configurations, Sockets

2.4.2Memory configurations

You may install 512 MB, 1 GB, and 2 GB unbuffered non‑ECC DDR2 DIMMs into the DIMM sockets.

Mode

Single-Channel

Dual-channel (1)

Dual-channel (2)

	Sockets
DIMM_A1	DIMM_B1	DIMM_A2	DIMM_B2
-	Populated		-
Populated	-	-	-
Populated	Populated	-	-
Populated	Populated	Populated	Populated

•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 chipset resource allocation, the system may detect less than 8 GB system memory when you installed four 2 GB DDR2 memory modules.

•If you install four 1 GB memory modules, the system may detect less than

3 GB of total memory because of address space allocation for other critical functions. This limitation applies to Windows Vista 32-bit/Windows XP 32-bit version operating system since it does not support PAE (Physical Address Extention) mode.

•If you install Windows Vista 32-bit/Windows XP 32-bit version operating system, we recommend that you install less than 3GB of total memory.

Notes on memory limitations

•Due to chipset limitation, this motherboard can only support up to

8 GB on the operating systems listed below. You may install a maximum of 2 GB DIMMs on each slot.

64-bit

Windows XP Professional x64 Edition

Windows Vista x64 Edition

2-14 Chapter 2: Hardware information