# Confusion about CPU temp calibration

#### BobboBananna

##### Distinguished
From this guide, as I understand it, following the instructions there I am supposed to calculate the Tcase idle temperature with the formula "(X+Y)/2 + Ambient=Tcase idle" wich in my case is 30C because the CPU is QX9650 with stock cooler and the ambient temp is 22C and therefore calibrate the Tcase reading in SpeedFan to read 30C (it currently reads 37C) and then, at load, calibrate the Tjunction temps for the individual cores to read exactly 5C more than Tcase at load (right now the different cores don't even read the same temps when running Small FFT-s with Prime95, and they should, right?).

So, what I'm confused about is:
1. Am I supposed to calibrate SpeedFan to read Tcase as 30C when idle?
2. Am I supposed to calibrate SpeedFan to read all four Tjunction as Tcase+5C when running prime95, thus causing all 4 cores to read the exact same temperature when at 100% load?
3. There's a 10C difference in readings at idle from Real Temp and SpeedFan (uncalibrated). The difference is 8C when at full load. Real Temp shows lower readings. Strange, isn't it?
4. There's also a 7C difference in readings for Core0 and Core1, 3C for Core1 and Core2 and no difference for Core2 and Core3 at full load. Shouldn't the temps at full load be equal between cores, even when not calibrated, because all four cores are equally loaded at 100%, right?

#### CompuTronix

##### Intel Master
Moderator
1. Correct
2. Correct
3. What Tjunction Max in which version of Real Temp?
4. In a perfect world with perfect 45nm sensors which Intel calibrated perfectly at their factory? Guaranteed!

Comp

#### BobboBananna

##### Distinguished
Thanks for clearing that up for me.
I didn't say anything about Tjunction Max. What I meant was that Real Temp 2.70 simply has all of it's Core Temperature readings at 10C lower than the ones in SpeedFan 4.37. It's probably only because I haven't calibrated SpeedFan yet.