Hmm, got my 7970 (Club3D, 975/1375 standard clocks) running with a Zalman ZM600-HP at the moment, and it performs great in BF3. After gradually increasing the clocks to 1025/1400, my rig just shut down during Metro 2033. I just booted again, and the fan of the 7970 started spinning like crazy, sounded like the fans were at 50/60%+ When I saw the login screen, it went to normal speeds (20%) again. Windows didnt show me any errors.
My CPU is running at 4.6ghz, so I think this happened due to power shortage. Or should I look into something else ?