Im running a pny geforce 6800 ultra. Runs fine in windows - but than reboots randomly during any sort of 3d use. (I.E. Gaming) I have a 500 watt Antec power supply, so I don't believe that is the issue. The card idles at 67 degrees Celsius, although it appears to be dropping as I clocked the 2d and 3d clocks down to 300 mhz w/ coolbits. My case is cooled very well, with plenty of air flowing over the card. I will be trying it with the new clock settings shortly, hopefully that will help.