Here's my situation; I have a Velocity Micro pre-built system w/Asus P5N-E SLI 650i Mobo. With my existing 4 1G sticks of Corsair PC2-5300 (667mhz) Ram, all is good. When I remove them and install 2 2G sticks of Corsair PC2-6400 (800mhz) RAM, my system freezes at the memory portion of the POST on the first boot of the day... or after the machine has been down awhile. Re-boots (and boot-ups after only a short down time) work fine. The freeze only seems to occur after the machine has been off for awhile. There is no O/Cing; all is stock. The memory showed no errors after 7 passes with Memtest86. The CMOS battery is new.
I have tried leaving the BIOS settings at "Auto", and have tried "Manual" as well. I have the memory voltage set to the recommended 1.8v and the timings set to the recommended 5-5-5-18 2T. This is the 2nd brand of 800MHZ RAM I have tried, and I have had this same problem with both. The BIOS is a late version designed for 800mhz memory and 1333 mhz FSB, and it recognizes PC2-6400.
I have tried leaving the BIOS settings at "Auto", and have tried "Manual" as well. I have the memory voltage set to the recommended 1.8v and the timings set to the recommended 5-5-5-18 2T. This is the 2nd brand of 800MHZ RAM I have tried, and I have had this same problem with both. The BIOS is a late version designed for 800mhz memory and 1333 mhz FSB, and it recognizes PC2-6400.