What is the default value for NB vid? Isn't that 1.15V? That would mean you're pumping a whopping 1.64V into that CPU-NB!

I think i degraded the NB of my 940 by pumping 1.47V into it with the stock cooler. It was always able to run 2.8GHz with NBvid at auto but after i pushed that volts through it i never got it to do that again.

It could have been the 2,5Vdimm i used as well, i don't really know but i'd rather be safe than sorry so i will stay below 1.45V on th NB to be sure.