What is TCASE vs. Tjunction? These terms are related to processor temperature for desktop and mobile systems base on Intel® processors. To allow optimal system operation and long-term reliability, the processor must not exceed the maximum case temperature specifications as defined by the applicable thermal profile.
TCASE is the temperature measurement using a thermocouple embedded in the center of the heat spreader. This initial measurement is done at the factory. Post-manufacturing,
TCASE is calibrated by the BIOS, through a reading delivered by a diode between and below the cores.
T
junction is synonymous with core temperatures, and calculated based on the output from the Digital Thermal Sensor (DTS) using the formula T
junction = (T
junction Max – DTS output).
http://www.intel.com/support/processors/sb/cs-033342.htm