I have two 8400 that stay around 60c Blend/OCCT/Prime loaded at 1.33v / 4.25ghz, and a third I'm helping someone with (805A) that jumps to 75c with only 1.3v / 4ghz.

I feel lucky that the two I own seem to have normal sensors. Interested to see what you guys find out about the chips that look as if they're running mad hot on medium volts.