Asus P5KPL/EPU - Manual (Page 23)

ASUS P5KPL/EPU 1-13
1.7.2 Memory configurations
You may install 512MB, and 1GB unbuffered non-ECC DDR2 DIMMs into the DIMM sockets.
• When using only one DDR2 DIMM, start installing it from DIMM_A1 or DIMM_B1 for
better overclocking capability.
• For dual-channel configuration (1), install two identical DIMMs in DIMM_A1 and
DIMM_B1.
• For dual-channel configuration (2), you can:
-
install four identical DIMMs in all four slots; or
- install one identical DIMM pair in DIMM_A1 and DIMM_B1 (yellow slots) and
another identical DIMM pair in DIMM_A2 and DIMM_B2 (black slots).
• 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 do any of the
following:
- Use a maximum of 3GB system memory if you are using a 32-bit Windows ® OS.
- Install a 64-bit Windows ® OS when you want to install 4GB or more memory on
the motherboard.
• This motherboard does not support DIMMs made up of 256 megabits (Mb) or less.
• This motherboard supports up to 4GB on Windows ® XP Professional x64 and Windows ®
Vista x64 editions.
• The default memory operation frequency is dependent on its Serial Presence Detect
(SPD), which is the standard way of accessing information from a memory module.
Under the default state, some memory modules for overclocking may operate at a lower
frequency than the vendor-marked value. To operate at the vendor-marked or at a higher
frequency.
• For system stability, use a more efficient cooling system to support a full memory load (4
DIMMs) or overclocking conditions.
• Some old-version DDR2-800 DIMMs may not match Intel ® ’s 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.