I think you misunderstood me, I have one stick of corsair xms pc3200 not twinx. Here's the story, whenever I run memtest86 at 200 fsb, no matter what the multiplier is or what the timings are, it freezes on test #5. At first I thought it was the ram and I posted in the corsair help forums. Ram Guy replied saying to test the memory at 166 fsb and 2-2-2-5 timings and if it passes then it's not the ram but either the mobo chipset or the cpu. Well sure enough it passed without freezing, and it actually passed at 198 fsb and 2-2-2-5 but at 200, always freezes. So I'm thinking maybe it's my mobo chipset but I have the C1 stepping and isn't that supposed to handle 200 fsb? So now my theory is maybe my ram doesn't like my board or vice versa. Oh btw, I have the vdimm at 2.8, and the vdd at 1.7.