Originally Posted by RejZoR
I've tried overclocking with MSI Afterburner, overvolting, raising Power limit, nothing. It works for a while perfectly, no artifacts, but then GPU just restarts itself and the game freezes for couple of seconds.
You've got the R6950 Twin Frozr III PE/OC (850Mhz or 6-7% OC), and you get it another 25Mhz above that before the game just freezes on the screen? I would say the card should be expected to give you 900Mhz normally. I don't know it might be the "luck of the draw" and you got a bum card, or a PSU and/or mobo that's acting up. Have you monitored the temperature while in a stress test? Heck I might say remove and re-seat the cooler with good thermal compond.