Different programs, different readings.

h11

h11

h11

Associate
Joined
20 Oct 2009
Posts
91
Just installed my new NH-D14 CPU cooler on my i7 920 (Stock speeds), booted up Speedfan and was impressed with the readings. All core temps were between 23-25C.

After reading around I've seen a lot of people seem to recommend Core Temp, so I downloaded it and got totally different temp readings, around 38C with a max of 42C.

Which one is correct?
 
Coretemp is likely to be correct.

Speedfan used to give me readings that were the same as openhardwaremonitor and realtemp, so I used speedfan. But then I noticed that it was about 15-20'c too cool, sometimes giving my temps as -5'c :p
So I'd advise downloading realtemp/openhardwaremonitor and checking them to confirm that coretemp is correct :)
 
The issue with all of these utilities that the CPU provides its core temps relative to the max that that CPU allows (sometimes known is tj max). If the utility has the right tj max for your CPU it should display the correct temps. CoreTemps displays the tj max (whereas others don't appear to) and appears to generally do a better job of having accurate tj max values. If you like speedfan you can adjust its temperatures with an offset if you can work out what that offset should be (and this is what I have done).

This is what an Intel document says about thermal readings (tj max is the temp that the temperature circuit control or TCC is activated):

Platform Environmental Control Interface (PECI) DC Specifications

PECI is an Intel proprietary interface that provides a communication channel between Intel processors and chipset components to external thermal monitoring devices. The processor contains a Digital Thermal Sensor (DTS) that reports a relative die
temperature as an offset from Thermal Control Circuit (TCC) activation temperature.
Temperature sensors located throughout the die are implemented as analog-to-digital converters calibrated at the factory. PECI provides an interface for external devices to read the DTS temperature for thermal management and fan speed control. More
detailed information may be found in the Platform Environment Control Interface (PECI) Specification.

If you want more light reading see:

http://download.intel.com/design/processor/datashts/320834.pdf

Or you could search the Intel site for your processor.
 
Last edited:
This is an interesting thread on the subject:

http://www.tomshardware.com/forum/242940-29-core-temp-inaccurate-core-temperature-readings

Start at the reply starting "To all. I kind of extracted what I thought to be the core of what was said in that 8 page thread. Proof read and maybe you can correct oversights or blatant errors. I'm trying to get everything in one place for people that also don't get the temp guide or might like to see a different approach to it....". If you believe it, the actual temp depends upon a factory set limit and the voltages and TCC is not queriable directly (doh intel!).

There is a suggestion for finding it out in this thread if you are really keen.
 
robj20 said:
Coretemp always seems to give consistantly the most accurate readings for me.
Click to expand...

I agree, although if you believe the thread I posted a link to they are still a guess (based on CoreTemp's assumption about Tj Max). However since CoreTemp also displays distance to Tj Max you get a solid idea how far away you are from melting the processor which is probably the most important piece of information when overclocking.
 
You must log in or register to reply here.
Back
Top Bottom