Just a note on ATITool (beta 0.27). Personally, it's a total annoyance to have to boot and hit F8 to defeat the driver signing check in Vista x64 (especially since it's just a DRM thing by MS anyway and adds very little to security). But I digress. With 158.18, ATITool can be used to control your GPU clocks (no surprise), but every time I did so, after getting out of any 3D software, in approximately 10 minutes and while at the Vista Desktop, Vista would BSOD with a really crazy error about the "Memory Management System". GPU temps were fine. I've never seen this variety of BSOD, either in XP, XP x64 or Vista. I'm going to wait until the nVidia drivers support OCing.