Asus Crosshair V Formula/ThunderBolt - Manual (Page 36)

Memory configurations
You may install 512MB, 1GB, 2GB, 4GB, and 8GB unbuffered ECC and non-ECC
DDR3 DIMMs into the DIMM sockets.
• 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, refer
to section 3.3 Extreme 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.
• 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 red slots for
better overclocking capability.
• Always install DIMMs with the same CAS latency. For optimum
compatibility, we recommend that you obtain memory modules from the
same vendor.
• When overclocking, some AMD CPU models may not support DDR3 1600
or higher frequency DIMMs.
• 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.
For more details, refer to the Microsoft® support site at
http://support.microsoft.com/kb/929605/en-us.
• This motherboard does not support DIMMs made up of 512Mb (64MB)
chips or less (Memory chip capacity counts in Megabit, 8 Megabit/Mb = 1
Megabyte/MB).
2-6 Chapter 2: Hardware information