Asus P5E-VM DO User Manual - Page 32

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. • 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 GB memory modules, the system may detect less than 3GB because the address allocation for other critical functions. This limitation applies to Windows® Vista 32-bit/ Windows® XP 32-bit version operation system since it does not support Physical Address Extension (PAE) mode. • This motherboard does not support memory modules made up of 128 Mb chips or double sided x16 memory modules. 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. 64-bit Windows XP Professional x64 Edition Windows Vista Professional x64 Edition • Some old-version DDR2-800 DIMMs may not match Intel® On‑Die‑Termination (ODT) requirement and will automatically downgrade to run at DDR2-667. 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. • The total memory may has 8MB reduction under Single Channel mode, and 16MB reduction under Dual Channel mode because the address space is reserved for the Intel® vPro™ Technology and the Intel® Quiet System Technology. 1-20 Chapter 1: Product introduction