I finished building my new PC last week (first time doing it) and everything ran smoothly at the start. Now, however, my GPU's core clock is locked at 539mhz and won't move. I've tried restarting, uninstalling and re-downloading the drivers, updating my BIOS, everything, with no change. It's idling around 60 degrees, also. I have a 5820K with 16GB of ram and I can't even pull a 5,000 on firestrike. I've read where some other people have had similar issues with their cards and they all get stuck at the same 539-540mhz, but I haven't read of a definite solution. Anyone have input?