How is each core temperature measured?

[Peteman100]

How do programs like Realtemp and Coretemp measure the temperature of each core? I was told that Intel processors only have a single temperature sensor built-in. So do they extrapolate each value?

 

[Nenu]

Each core as an on die sensor.

 

[Peteman100]

Each core as an on die sensor.

Seriously? I had an intel support person insist that there is only one on my Q9550! Any idea where I might find some documentation stating that there is a sensor on each core?

 

[BillParrish]

Intel.com tech journal.

That Intel support person should be shot or have his tongue cut out or better yet cut out his tongue and shoot the tongue, twice.

Each core has several temp sensors in various places inside the core die that report the highest temp for that core as part of the DTS (Digital Temp Sensor). The "number" the DTS reports to a user readable register is not a temp but a number that indicates the number of deg C until the processor reaches a factory calibrated set point in which the CPU thinks it is getting too hot and sends out an interrupt to run the fans at 100% speed. About 10-20C above that if temps keep rising it will trip the catastrophic temp point and shutdown. Coretemp etc. read that number and do some math based on the "I am too hot" trip point to try to provide a number that corresponds to a actual temp. Your quad has 4 cpus each with its own DTS and reports 4 accurate numbers.

Here is an older article I bookmarked that explains the technology which was first used on the mobile CPUs and of course this technology has only been further refined and used on all Intel Core 2 Duo and quad chips to date. I have newer stuff but its overly technical.

Read the "Power and Thermal management..." article.
http://www.intel.com/technology/itj/2006/volume10issue02/vol10_iss02.pdf


If you look for the technical documents for your processor on Intel.com and read the Thermal and Mechanical Guidelines and the Data sheet the DTS is mentioned in a general way.

Here is more with some links to the documents for the Q6600.
http://hardforum.com/showpost.php?p=1031827510&postcount=31

 

[Arcygenical]

Yes, there is a thermistor near the main Execution unit of each core... And an overall chip temperature thermistor for determining Tcase temperatures.

 

[Peteman100]

Thanks guys!