1.What exactly is the Tjunction max temperature? Is this the maximum temp any of the cores can reach before the CPU shuts down?
2. If my Tjunction max is 100 celsius, at what temp should I start to worry that the cores are getting too hot?
3. What is the CPU max case temp?
4. Is the delta to Tjunction max temp simply the difference between the Tj max and current core temp?
In most processors there are two thermal monitoring elements: Tjunction and Tcase (one for each core on junc). Tjunction is the more important as that is actually a diode on the semiconductor material who's knee voltage changes based upon temperature. The Tcase is a thermal element on the metal shield that surrounds the processor cores. The Tjunction will always be higher than the case. You are correct about the max temp.
The temperature that cores start to have issues varies from processor model to processor model so how hot yours can go depends on what model you have. It varies based on the semiconductor material, the trace material, the transistor size, etc..
Case temp is the same concept as the junction temp but less precise and more of a precaution in case the junction temp monitor fails.
I am not sure about number 4.
Edited by dBs - 5/6/10 at 4:19am