Arch Linux

cuihao

Member

Registered: 2011-03-19

Posts: 27

Overheat causing by broken CPU sensors?

(Sorry for my poor English, I'm not native)

My CPU is AMD Athlon(tm) 64 X2 Dual Core Processor 5200+, not overclocked.

Since this summer, my PC always shutdowns automatically because of CPU overheat when compiling codes. As winter comes, it still happens frequently.

I notice that the core temperature changes very violently. For example, if I run 2 cpuburns, core temperature will raise from about 30C to over 80C (even 100C) in less than 5 senconds, after I suspend it, CPU will cool down in no time. However, while CPU sensors gives high temperature, CPU temperature given by motherboard is still very low:

atk0110-acpi-0
Adapter: ACPI interface
......
CPU Temperature:    +37.0°C  (high = +60.0°C, crit = +95.0°C)
MB Temperature:     +29.0°C  (high = +45.0°C, crit = +95.0°C)

k8temp-pci-00c3
Adapter: PCI adapter
Core0 Temp:   +76.0°C  
Core0 Temp:   +81.0°C  
Core1 Temp:   +71.0°C  
Core1 Temp:   +80.0°C

I have felt the temperature by touching CPU radiator, and I thought it was not so hot as sensors given at all. So I doubt that my CPU sensors broken.

What do you think? And how can I prevent such overheat? Thanks.

---

Forgive my poor English. I am a senior student from China.

signor_rossi

Member

Registered: 2007-08-24

Posts: 257

Re: Overheat causing by broken CPU sensors?

Hmm, this is not easy to troubleshoot, could also be a hardware problem.
First, do you have an option to check the idle temperatures in the BIOS screen? That might give you an idea which one of your temperature readings from your sensors command is more accurate.
The situation you describe with the temperature rising very fast under load and falling fast when idle seems sound to me, with the CPU clock speed-steeping to a higher clock under load and falling back to a lower clock speed when idle. You do have speed-stepping configured, right?
https://wiki.archlinux.org/index.php/Speedstep
My first guess is that the connection between CPU and FAN heat-sink is lacking, i.e. too much/not enough/poorly applied thermal paste or maybe the heat-sink or the fan are dusty or the fan itself is whacky (BTW does the FAN spin faster when the temperature rises?), you might check these things first.