Asus P5Q TURBO - Manual (Page 29)

ASUS P5Q Turbo 2-11
Chapter 2
2.4.2 Memory configurations
You may install 512MB, 1GB, 2GB and 4GB unbuffered ECC and 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.
• We recommend that you install the memory modules from the yellow slots for better
overclocking capability.
• 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 on the
motherboard.
• This motherboard does not support DIMMs made up of 256 megabit (Mb) chips or
less.
• 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, see section 3.5 Ai Tweaker menu for manual memory frequency
adjustment.
• For system stability, use a more efficient memory cooling system to support a full
memory load (4 DIMMs) or overclocking condition.