Asus P5B 32-bit, 64-bit

• 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 XP 32-bit version operating system since it does not support PAE (Physical Address Extention) mode.

•If you install 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, but only DDR2-533 and DDR2-667 2 GB density modules are available for this configuration.

32-bit	64-bit
Windows 2000 Advanced Server	Windows XP Professional x64 Edition
	Windows Vista x64 Edition

•Some old-version DDR2-800/667 DIMMs may not match Intel®’s

On‑Die‑Termination (ODT) requirement and will automatically downgrade to run at DDR2-533. If this happens, contact your memory vendor to check the ODT value.

•Due to chipset limitation, DDR2-800 with CL=4 will be downgraded to run at DDR2-667 by default setting. If you want to operate with lower latency, adjust the memory timing manually.

•Due to chipset limitation, DDR2-667 with CL=3 will be downgraded to run at DDR2-533 by default setting. If you want to operate with lower latency, adjust the memory timing manually.

P5B Premium Series Motherboard Qualified Vendors Lists (QVL) DDR2-800MHz capability

Size	Vendor	Chip No.	SS/	Part No.	DIMM support
			DS		A*	B*	C*
512MB	KINGSTON	K4T51083QC	SS	KVR800D2N5/512	v	v	v
1024MB	KINGSTON	K4T51083QC	DS	KVR800D2N5/1G	v	v	v
1024MB	KINGSTON	Heat-Sink Package	DS	KHX6400D2LL/1G	v	v	v
1024MB	KINGSTON	Heat-Sink Package	SS	KHX6400D2LLK2/1GN	v	v	v
2048MB	KINGSTON	Heat-Sink Package	DS	KHX6400D2K2/2G	v	v	v
512MB	Qimonda	HYB18T256800AF25F	DS	HYS64T64020HU-25F-A	v	v	v
256MB	Qimonda	HYB18T512160BF25F	SS	HYS64T32000HU-25F-B	v	v	v
512MB	Qimonda	HYB18T512800BF25F	SS	HYS64T64000HU-25F-B	v	v	v
1024MB	Qimonda	HYB18T512800BF25F	DS	HYS64T128020HU-25F-B	v	v	v
512MB	SAMSUNG	EDD339XX	SS	M378T6553CZ3-CE7	v	v	v
256MB	SAMSUNG	K4T51163QC-ZCE7	SS	M378T3354CZ3-CE7	v	v	v
512MB	SAMSUNG	ZCE7K4T51083QC	SS	M378T6553CZ3-CE7	v	v	v
1024MB	SAMSUNG	ZCE7K4T51083QC	DS	M378T2953CZ3-CE7	v	v	v
512MB	Hynix	HY5PS12821BFP-S5	SS	HYMP564U64BP8-S5	v	v	v

2-14 Chapter 2: Hardware information