The P3V4x is infamous for giving really bad and often wrong readings off the temp diode. I have a 566 @850, and on the p3v4x, the temps go from 40ish to 61oC in a second. However, when I put it in a CUV4x, it doesn't spike like that at all, and usually stays in the 40-50 range. I'm using a golden orb, so it might not be as cool as you'd expect. I'm also using a voltage of 1.75 BTW