A knowledgeable person on Tom's Hardware told me a long time ago that the Core 2 based CPUs contain a separate temperature sensor embedded in the center of the CPU. I used to always think the CPU temperature data that software reports was coming from a sensor in the socket. Wherever that sensor is, some motherboard manufacturers may have calibrated it based on inaccurate data coming from the core sensors. In situations where this is true, that temperature data might not be accurate so trying to compare to it could be pointless. I've got a board where this sensor can show over 105C when the core sensors are still just under 100C. If the core sensors are located on the hottest spots on the core then that's impossible. If this data was accurate, this other sensor should be reporting ~20C less than the peak core temperature when the CPU is fully loaded. Heat dissipates very rapidly over a short distance at full load. I find the resume from stand by temperature over night and comparing that to the room temperature works best.