Intel TAT / CoreTemp / IDCC all different temperatures....

[unclewebb]

The Tjmax for nay core 2 chip is not necessarily 85 or 100 exactly.

Is there any documentation from Intel or any evidence from other users to support that? I'm not saying it's not true. I'm just interested like everyone else in what's really going on.

For my E6400 Revision B2, CoreTemp uses this formula:
reported temp = 85 - DTS

CoreTemp reports 85C when DTS equals zero.

During testing, TAT first started to report, "Thermal Monitor Active" in red for Core0 when DTS was at 2 so CoreTemp was reporting 83C. At this point the reported MHz is not yet reduced but the performance of the processor starts getting reduced internally to try and control the temps. CPUz will still be reporting full MHz but performance is reduced.

If the temperature of the processor can still not be controlled using this first thermal throttling technique, then the processor MHz will also be reduced. If the temperature still can't be controlled then finally the "catastrophic shutdown detector" is enabled and the processor shuts down.

Both methods of throttling will result in reduced performance for your processor. At stage 1, the reported MHz might still show your CPU at full speed but performance is already being reduced.