Core Temps vs. Chip Temp

Those temps look pretty average for a quad-core CPU. One thing I'd like to clarify - where are you getting the core temps from?

I've heard that Core Temp gives the most 'correct' readings of temperature. Also, when have you read the BIOS temperature reading? On inital startup? After restarting after running your system for a while?

Those temps are odd to me, speedfan almost always shows my E6750's 1st core as 1 degree under the CPU temp and the 2nd 1 degree over the CPU temp with little variation. A 20c difference does not seem right at all, and my CPU temps under speedfan are always identical to BIOS readings.

Check the temp guide, it explains it well.

http://www.tomshardware.com/forum/ [...] ture-guide

If you want accurate temperature readings a Core 2 Duo/Quad take a look at Real Temp:

http://www.techpowerup.com/realtemp/

Core temperature = TJMAX - DTS Value

TJMAX is the maximum temperature a core can run at before it initiates thermal throttling. Intel does not publish this value for its Core Line of desktop processors.

DTS (Digital Thermal Sensor) is the digital thermal probe inside each processor core. The probes do not measure the core's temperature, rather the distance the core is away from TJMAX. In other words, the DTS value is used to measure how close the core is coming to the temperature at which it will begin throttling. So, if the DTS value is 40, then your core can heat up 40 degrees before throttling. It the DTS value is 2, then your processor is about to start throttling (once DTS value = 0). DTS was never meant to be a measure of core temperature, but a way to signal the processor to prevent it from overheating.

By this formula it is possible to calculate the core temp, but you need to know TJMAX (a fixed value) and the current DTS value. Luckily the DTS can be read from the processor and this is what programs like Real Temp, Core Temp, and Speedfan use. TJMAX is the big question. Intel has never released this information for the desktop Core products. They did actually release it for their mobile 45nm Core products: 105 degrees C. This is what Core Temp and Speed Fan use for their TJMAX. However, it has been found that this value is too high for the desktop Core chips.

The author of Real Temp actually used a Infrared Thermometer to measure a variety of Core 2 Duo's and Quads (also, Pentium Dual Core, since they're based on the same architecture) and discovered that most chips have a TJMAX of 95 degrees C. A few models are 85 degrees C. This is why Core Temp and Speedfan read the temperature 10 degrees higher than Real Temp. They guess at the value of TJMAX wheras the Real Temp author actually measured and calculated it.

In his testing, he replaced Core Temperature with the value he was measuring from his IR Thermometer (accuracy is +- 1 degree C of actual core temp)

Measured Temp = TJMAX - DTS

so

TJMAX = Measured Temp + DTS

He can then calculate TJMAX because he has the measured temp from his thermometer and he knows the DTS value reported by the chip.

You can read a lot more about Real Temp, the testing methods, and more here:

http://www.techpowerup.com/realtemp/docs.php

and here:

http://forums.techpowerup.com/showthread.php?t=64185

and here:

http://www.xtremesystems.org/forum [...] ost2809778