usually the motherboard is the main cause for that problem, unsupported sensors i think.The only problem with E8400s (which makes me EXTREMELY ANGRY) is that you cant trust anything program for temperatures. Everything will give u a drifferent reading, wont go under a certain temp... its so messed up. I wish I could get a different CPU that works right with hat stuff. I EASILY can get mine to 3.8ghz.