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SpeedFan and CoreTemp give different temperatures

Last response: in CPUs
April 10, 2011 7:50:52 PM

So I installed SpeedFan and it looked like my CPU was idling in the 80's! And then I used CoreTemp and it said the cores are in the 30's. Is there a problem here I need to fix?

a c 198 à CPUs
April 10, 2011 7:59:34 PM

I use Real Temp. It seems to give me the most consistent results.
a b à CPUs
April 10, 2011 8:05:40 PM

Speedfan is getting old and many people have had bad readings or incorrectly labled readings

I use Coretemp,Realtemp and HWmonitor and mainly use Coretemp

All three show different readings LOL

There is the Great Myth of Temp Monitoring which is
that is exact idle/load temps

I have been obsessed with temps for about two years

after two years of google research, experimenting/testing and having journals with temps and worrying about 2 or 3 degrees idle temp differences that
after recent reading and my own conclusions
that using temp software is useless for real readings

Stick with one program (coretemp is good) and just use it as a baseline

If you properly applied paste and a decent fan/heatsink in a temperature controlled
room that hever goes over 80F then you never have to worry about a temp
problem unless your fan stops working

If coretemp is reading 30c at idle with cooling functioning properly then realize
that is NOT really at 30c
that is your baseline temp
as long as you dont see that raise dramitcally (bad fan problem)
and your room doesnt go over 80F
than dont even worry about it
the idle temp is just an indicator that the cooling is working not EXACT temp

Intel themselves stated that the DTS (digital thermal sensor) used in Core series
is highly inaccurate at idle (+/- 10 degrees C)
It is only reasonably accurate at LOAD MAx temps

AND Intel uses Tcase temps in specs (temperture of CPU package- the outside of the cpu heatspreader) and not Tjmax
In fact it is hard to find an accurate TJMax temp for any cpu

I have seen my C2D listed from 85c-100c for Tjmax with everybody disagreeing on it

Also the 45nm series cpus particulary have a problem with accurate temps especially at idle

Basically run Prim95 (small ffts) for 20 minutes with Coretep and if your CPU
doesnt go over 70C then dont even worry unless your house goes over 80F in the summer

Temperature monitoring is a trap for Obsessive/Compulsive personalities to freak out about
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April 10, 2011 8:57:21 PM

Okay, so I checked RealTemp and it said I'm idling in the 30's, so I think I'm okay. I would still like to know why SpeedFan gives a temp of 80?

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a c 112 à CPUs
April 10, 2011 9:03:50 PM

speed fan doesnt read i7 cpu's very well. often its 10 degrees off. especially if you use an odd multi like 19 or 21.
use realtemp or coretemp.
April 21, 2011 3:48:18 AM

Best answer selected by NakedSnake.
March 16, 2013 3:04:10 AM

NakedSnake said:
Okay, so I checked RealTemp and it said I'm idling in the 30's, so I think I'm okay. I would still like to know why SpeedFan gives a temp of 80?


Allowing for a little measurement error I think its safe to say one is C and the other is F