Inaccurate core temp readings

[sitnet]

Hey guys

Ok so I have a Intel DP45GS board and Q8400 proccesor.

On speedfan (latest final version) my core 1 to 4 readings are about 50C at idle, but my CPU reading is about 32 to 35.

Why is this that the core readings differ so much from the CPU reading? BTW I have a Coolermaster elite 430 case with a front 12CM fan, a top 12CM fan and a rear 8CM Vizo windstorm running at 3000RPM.

Now those core temps seem much too high, so what's going on?

Thanx

 

[UnUnOctium]

http://en.wikipedia.org/wiki/Thermal_resistance

http://www.arcticsilver.com/images/p4_as_dab2a.jpg

 

[sitnet]

Ok wait, I know what thermal conductivity is (I did a online physics course from UCberkley, and I definetly understand the physics behind thermal conductivity, so I don't need to read up on that). Just tell me what the picture of the CPU means?

 

[UnUnOctium]

Ok wait, I know what thermal conductivity is (I did a online physics course from UCberkley, and I definetly understand the physics behind thermal conductivity, so I don't need to read up on that). Just tell me what the picture of the CPU means?

The actual on-die sensors are inside the CPU core. The motherboard thermal sensors are on the motherboard. Both temperatures won't be the same.

 

[Gnome]

The short of it is that Intel use inexpensive temperature sensors on the CPU. Those sensors aren't accurate at temperatures below the throttling threshold. Meaning the sensors are designed to only be accurate in a narrow temperature band.

Try using RealTemp but even then, as long as the thermal trip is triggered on the CPU, everything is fine.

But then again your CPU cooler may not be that good and the actual idle temps are really 50 degrees. My previous computer (which I have turned into a NAS) has an Intel Core 2 Duo E7400 with "stuck" temperature sensors. The temperature is always reported as 36 and 40 degrees respectively for the cores. Unless I run Prime95 for a few minutes after which I can actually reach 50 degrees. Point being that CPU cannot read lower than 36 degrees on the one core and 40 degrees on the other. CPU is cooled by Thermalright 120 Ultra Extreme.

 

[sitnet]

Ok thanx for all the help. I think maybe the CPU fan is not mounted properly, will remount it later today, OH great I'm out of paste, guess I'll have to go and buy...

But I am going to buy a better CPU fan. Thinking of getting the Coolermaster hyper 212, is it any good, because it is really cheap (R350 incl. delivery from prophecy)?

And I see it fits multiple sockets, how does that work?