So I got a new pair of HIS 6950s, flashed bios to 6970s. + 20% voltage, running 880 MHZ core & 1375 memory. And my L4D 2 crashes every time after 15-40 mins of playing. The crash either results in blue screen or the game freezes and the colors turn into 16 bit ( pink colored screen ). It only happens with L4D 2 though. UT3, WoW, Crysis Warhead runs fine. Original L4D runs fine also! Don't have any Dx11 games to test with yet, but... I ran Unigen Heaven benchmark 3 times and no errors what so ever. Mode I ran in Dx 11 Stereo 3D : Disabled: Shaders : High Tesselation : Extreme Anistrophy : 16x AA : 4x Res : 1920 x 1080 Score : 1274 GPU load for both cards while playing Crysis, L4D2 & Unigen are all at 98%. So it shouldn't be that my cards sucking too much power for my 750W psu. Anyone has any idea what's causing this blue screen? Maybe it's pre-mature drivers?