My i7 920 seemed to be stable at 3.8GHz at 1.175v, which seems rather low for a 920 at that speed. However, when I want to jump to 4GHz, it takes at least 1.3v to be stable. This seems somewhat higher than what it normally takes for a 920 to get to 4GHz. I've heard of some people lowering the CPU PLL voltage (not QPI/DRAM voltage) and improving stability. Has anyone had any luck with this? What PLL voltage did you use? I tried 1.5 PLL voltage and lowering to 1.275v vcore, but it crashed in OCCT.