i7 950 MAX Overclock on air

[unclewebb]

Hi Comp,

I had a look at the Intel documentation you posted and I saw the chart that shows the difference between the peak TCase diode temperature vs the peak core temperature. There is no temperature scale on the left hand side of that chart. I don't agree with your assumption that the scale is 1C per division. I think the scale is more likely 5C per division. If that is so then maybe the graph shows that there can be as much as a 26C gradient between TCase and core temperature depending on what program you're running.



That would make a lot more sense and would agree with the testing that rge did when he drilled a hole in the middle of his Core 2 CPU and mounted a calibrated thermocouple in the geometric center like Intel recommends for monitoring TCase temperatures. I think when he was running Prime95 he was seeing gradients between these two temperatures in the 25C range.

I'll send him a PM and a link to this thread so hopefully he can share some of his testing. He might still have a link to the YouTube video he did when testing.

Here's a quote from that Intel paper:

"It can be seen that large temperature gradients exist on the die. It also can be noted that some workloads display high temperature gradients while other have no offset. Thermal control algorithms need to prevent the hot spot from exceeding the max temperature specification. It is possible to mitigate the temperature difference by applying a fixed offset to the diode reading. This obviously is a non optimal solution as the workloads with low offset will be penalized by the unnecessary temperature offset. The use of digital thermometer provides improved temperature reading, enables higher CPU performance within thermal limitations and improves reliability."

My interpretation of that paragraph is this. Intel introduced core temperature sensors so they could better control thermal throttling and thermal shutdown without having to penalize users with early thermal throttling based on the inaccurate TCase diode temperature. Thermal control in modern Intel CPUs is controlled by the core temperature sensors to provide users with maximum performance without having to worry about thermal throttling until absolutely necessary based on the hottest spot on the core.