Asus M3A78-CM - Manual (Page 27)

ASUS M3A78-CM 1-15
• When using only one memory module, start installing the DDR2 DIMM from
slot DIMM_A1 or DIMM_B1 for better overclocking capability.
• For dual-channel configuration (2), you may:
- install identical DIMMs in all four sockets OR
- install identical DIMM pair in DIMM_A1 and DIMM_B1 (yellow sockets)
and another identical DIMM pair in DIMM_A2 and DIMM_B2 (black
sockets)
• Always use identical DDR2 DIMM pairs for dual channel mode. For
optimum compatibility, we recommend that you obtain memory modules
from the same vendor.
When you install a total memory of 4GB or more, Windows ® 32-bit operation
system may only recognize less than 3GB. Hence, a total installed memory of
less than 3GB is recommended if you are using a Windows 32-bit operation
system.
64-bit
Windows ® XP Professional x64 Edition
Windows ® Vista x64 Edition
The motherboard can support 8 GB physical memory on the operating system
listed below. You may install a maximum of 2 GB DIMMs on each slot.