Memory Configurations - Asus P4P800 User Manual

2.5.2 Memory configurations

You may install 64MB, 128MB, 256MB, 512MB, and 1GB DDR DIMMs into
the DIMM sockets using the memory configurations in this section.
Important notes on memory configurations
1. Installing DDR DIMMs other than the recommended configurations
may cause memory sizing error or system boot failure. Use any of
the recommended configurations in Table 1.
2. In dual-channel configurations, install only identical (the same
type and size) DDR DIMM pairs for each channel.
3. Always install DIMMs with the same CAS latency. For optimum
compatibility, it is recommended that you obtain memory modules
from the same vendor. See list of qualified vendors on page 2-13.
4. Make sure that the memory frequency matches the CPU FSB
(Front Side Bus). Refer to Table 2.
5. DIMMs installed into any three sockets will function in single-
channel mode.
6. When all four sockets are populated with 1GB DIMMs (total 4GB),
the system may detect only 3+GB (a little less than 4GB) due to
ICH5R resource allocation.
7. Double-sided DDR DIMMs with X16 (databus width = 16-bit)
memory chips are not supported due to chipset limitation.
8. It is recommended to use the blue DIMM slots first.
ASUS P4P800 motherboard user guide 2-11