Wrong CPU temperature in BIOS ?!

[Alcyon]

Hi guys.

I have installed a NH-U12P SE2 cpu cooler (from Noctua) and softwares like RealTemp or CoreTemp read a temperature of around 26-28°C for the first core and ~22°C for the others BUT the BIOS is showing a temperature of 67-68°C. What the #?... It's two fans on a y-split cable (3 pin) connected on a 4 pin. What should I do? The motherboard is an Intel DP55KG and I have the latest BIOS version (KGIBX10J.86A.3456).

Update: I've been told that the problem is simply related to the amount of pins so a big bravo goes to Noctua. Their definition of "compatible" isn't the same as mine.

This message can be deleted.

[Fuzzfas]

You say the pins are the problem, i hope so. If you ask me, i don't see what's the connection between the fan's pins and BIOS reading the motherboard sensor reading...


I haven't used Real Temp but i have used Core Temp in the past. Core Temp, reports the die (cpu core) temperature. This temperature is always inferior to the "CPU" temperature, meaning the temperature on the surface of the CPU.

For example, this is my own (using HWMonitor):

http://img198.imageshack.us/img198/2545/46380042.png

CPU is at 32. That's also what the BIOS reports, because it uses an external sensor.

Then you have the "core" temperatures, 29 and 16 (all programs seem to show always my second core running cooler for some reason). This is the temperature, inside the CPU die, meaning inside the proper chip, not the temperature of the external surface of the CPU.


In your case, it could very well mean, that your external surface temperature is at 67, while your core temperature at 28...

See here for more info:

http://www.tomshardware.co.uk/forum/page-221745_11_0.html

Anyway, just a guess. If you 're sure it's about the pins, ok. I just don't see, what's the pins got to do with the sensor that reads the temperature. AFAIK the fan pins control the fan speed and inform the BIOS abour fan RPM and that's it. The 4th pin, is used for automatic fan speed control for fans that have this feature. I also have pin fan on 4 pin motherboard header, but this doesn't influence temp readings.

If i were you i 'd rather think that's something wrong with the heatsink itself (not flat surface, inadeguate thermal paste, insufficient cooling capacity for the CPU's wattage), causing the CPU surface to overheat.