After much searching online, many people seem to share this problem.
I have four identical
2GB sticks of OCZ Platinum DDR2-1066 DRAM (confirmed via various apps) in my rig. But BIOS refuses to run them at anything above 800MHz (Dual Channel 400MHz x 2.) At startup, Bios reports my memory is "DDR2-800".
Originally, I was running only two 2GB sticks @ 1066, but after adding two more sticks of identical memory, BIOS's "Auto" settings downshifted to DDR2-800. I have tried setting the BIOS values by hand, increasing Dram voltage to 2.1v, bumping the mem-clock speed to 533, etc and so on. The result is always the same: an unstable system that crashes within minutes. It doesn't matter WHICH two sticks I use, as long as I'm only using two sticks of memory, I can run @ 1066.
But never with all four installed, and I have no idea why.
When I run "MemSet 3.5", it shows two of my DIMMS running @ "127ns" and two running @ "75ns". Setting all four the same (both 75ns or 127ns) causes Windows to crash. Here is the information:
I've read plenty of other posts
from people having nearly the same problem, but have yet to see anyone answer it. I've even tried overclocking my entire system to make up the difference, but that crashes too.
Anyone have an idea why this might be happening?
AMD Phenom II x4 920 (2.6GHz)
Gigabyte MA790GP-DS4H motherboard
four 2GB sticks of OCZ Platinum DDR2-1066 DRAM
1gb ATI Radeon 5850HD
PS: Another detail, if I use onboard video instead of my vidcard, all my ram will run @ 1066 just fine.