Real Temp - New temp program for Intel Core processors

[rosco]

There is a way to settle the issue. Anyone have a mobile dual core cpu (Tjmax documented in intel specs) and an accurate IR gun? IR the back of that cpu, and compare to core temp reading at idle with no heatsink and see if any gradient exists between die temp and IR to cpu. If gradient is near 0, then realtemp is accurate.

The theory that Tcase/cpu temp may in fact be near die temp most of the time is interesting. Intel talks about a die gradient of up to 10C between cores primarily since one core may be inactive and the 2 cores are separated from each other much further than either from IHS, and also transient hot spots. But when both cores are feeding the same temp to tjunction or tcase, especially across ?couple hundred microns of highly conductive material at idle... well they just don't say, but certainly would seem to be low.

So anyone with a mobile duo core cpu (with known Tjmax) and IR gun want to confirm one way or another?

There's always a gradient when dissipated heat travels from one point to another, it's physical. And please stop using IR guns, there are the worse instruments often used by people like a toy. It requires some cautions (like IR cams) because of the emittance problem of the surface we want to scan (why the yellow adhesive tape near the IHS on the first page? What's for? TC bonded to IHS?). Without preparation, pointing an IR gun on a +/- shiny surface like IHS or die is not good, the error will be higher because of radiation dispersion (gun don't measure temp but radiation) and gun will tell you a lower temperature than reality. If not adjustable, the gun is generally tuned for a 0.95 emittance, it's useful for black/matte surfaces (near black body) but not reflective/shiny/clear ones. Using a thermocouple bead is more useful and confident. You can also paint the IHS with black paint to get a emittance near maximum during measurements, that is 1. Moreover, you can't conclude anything with measuring Tcase (at the IHS center) for Tj or Tcpu because of the thermal gradients (a silicon die is ~0.04 °C/W through its thickness and there's TIM1 and IHS in the heat travel to take in account too for desktop CPU).

What matters is the real Tjmax, nothing else. Unfortunately Intel keeps its secrets like many others and it's a bit strange to not reveal such 'non critical' information I think... It's near 100 °C each time, that all. A bad guess and you have your cores under ambiant temp, so you know there's a flaw in that value. The absolute value will be false, but not the relative one. That don't make any great difference if the CPU is stable and not throttling, even with an o/c. What is observed here is related to the fact that nothing is linear again. You are pointing an IHS when its surface could have a 10 °C temperature difference under load, IHS temp is not uniform at all. That's a lot of flaws and errors at the final in the process...