Just for reference, how much of a temp. variation should there be on an i7-2600k overclock? As of now, I'm at 4.4Ghz with max temps of 59, 64, 64, and 67. Should they be more even? Almost 10C seems like quite a difference.
Thermal sensors are notoriously variable. For critical OC attempts they must be calibrated before being relied on. This involves loading the processor at 100% and then at incrementally lower loads through 5-10 stages. Since the errors may not be linear you need to find the variations at several points of load. Using Real Temps and Prime95 you can do this. However for most of us it is not necessary. From your post I would say the 64 reading is probably most accurate. What are the readings at 100% load after a few minutes?