Not sure why and it almost feels like more of a driver conflict. Xp and Vista both having issues.. one a bit different from the other but in Xp i saw my drive performance drop to 50% in HD sentinel. This started after installing the new video card. I am thinking a fresh install and an updated driver may help. Its only effecting my OS drive. Im ditching my Raptor and 500g samsung for a WD 640gb drive to save on power and noise. They keep saying its my PSU in the abit forum but the 520 corsair has no problems with the 8800GTS I had and my problems have been at idle and my O&O Defrag will hang when I try to use it. Any ideas?