pov 6800gt bench at 410/1151 given enough air she'll do that in games. i use a slightly modded default heatsink (single slot). removed the fan and replaced it with a former coolermaster hhc-01 fan plugged into the nb-socket (running 8v). at 12v it handles the load just fine. anything post 410ish is not really stable. either lower mem and run 420 or keep it there...