I am overclocking to 4.7 GHz currently and I've believed I've found the optimum settings 1.39V (offset mode), CPU PLL 1.75V.
One issue I'm having are the core temps, they are fairly cool, but one thing is very suspicious: the tempatures on core #0 are significantly lower than on the other cores. I've had this since the beginning (1.5 years ago when I overclocked to 4.3 GHz).
So you see core #0 is the suspicious one there. In task manager it's running at 100% just like the other cores, but after 10 hours of Prime95, the worker for core #0 is slowly starting to get behind: core 1, 2 and 3, are at test 8 at FFT length 14K, while core #0 is at test 1 of FFT length 14K. So in other words, it's a bit behind on the others.
My question is, is this all indicating that core #0 is a bad core or doesn't this mean anything at all?
Asus P8Z68-V Pro (B3)
Corsair Dominator 8GB (2x4GB) 2133 9-11-10-27-2T
Asus GTX 670
OCZ Vertex 4 128GB
Crucial M4 128GB
WD Cavair Black 1TB 7200 RPM 64MB
OCZ ModXStream Pro 700W
Scythe Mugen 2 REV B heatsink
Anyway, thanks guys, looks like I've got nothing to worry about. Belial, what you said actually makes lots of sense. The system is running on core 0 so it's obvious it's getting behind. Thanks for the input.