That problem is possibly down to a firmware bug with the P67 intel are currently working on a fix for. Disable all P states, CPU throttling etc and try then. My system is solid as a rock @ 4.6GHz even when the CPU hits 80c (IBT torture )
I'm stable at 4.8Ghz with 1.36v, no freezing, BSOD's or hiccups but nothing above that will work on this board. I have no idea why, I've tried many many settings and configurations. Fixed voltage wasn't any better than offset either, I still got BSOD's.
Asus Maximus IV Gene-Z
i5 2500k @ 4.5ghz
G.Skill Ripjaws X 16GB DDR3-1600
EVGA GTX 670 FTW 2GB
Creative X-Fi Xtreme
Corsairs HX1000 PSU
EK-Supreme HF: AquagraFX 680 GTX: MCP-355
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