Work around overheating with cpufreq-set 2012-06-07

One of my Gentoo boxes has overheating issues which I have yet to properly address on hardware level. Compiling something like Boost or Firefox results in a guaranteed emergency reboot, literally not cool.

The box has a dual core CPU with 2.53 GHz. Fortunately, it can be throttled to do operate at a lower frequency which results in less heat from the CPU.

Using cpufreq-info(1) I can see that the CPU is happy to operate under a few alternative frequencies:

$ cpufreq-info | fgrep 'available frequency' | head -n 1
  available frequency steps: 2.53 GHz, 2.53 GHz, 1.60 GHz, 800 MHz

Now different CPU governors give me different options:

  • Governor ‘performance’ runs at maximum frequency (i.e. 2.53 GHz), not cool
  • Governor ‘powersave’ runs at the minimum frequency (i.e. 800 MHz) where compilation may take forever
  • Governor ‘ondemand’ jumps from mode to mode depending on workload: still reboots from overheating
  • Governor ‘userspace’ allows me to keep the frequency at 1.60 GHz — nice!

You can check for availability of a specific CPU governor with

$ zgrep FREQ_GOV_ /proc/config.gz
CONFIG_CPU_FREQ_GOV_PERFORMANCE=y
CONFIG_CPU_FREQ_GOV_POWERSAVE=y
CONFIG_CPU_FREQ_GOV_USERSPACE=y
CONFIG_CPU_FREQ_GOV_ONDEMAND=y
# CONFIG_CPU_FREQ_GOV_CONSERVATIVE is not set

and make use of modprobe(8) as needed.

So with a single call

$ sudo cpufreq-set -r --min 1.60Ghz --max 1.60Ghz -g userspace

that box seems to stop overheating for now. Nice!

[EDIT]: What Robin is suggesting in the comments would make

$ sudo cpufreq-set -r --max 1.60GHz -g ondemand

on the shell.

Creative Commons License
The Work around overheating with cpufreq-set by Sebastian Pipping, unless otherwise expressly stated, is licensed under a Creative Commons Attribution-ShareAlike 3.0 Unported License.

2 Comments
robbat2 June 9th, 2012

Use ondemand w/ a max of 1.6Ghz, you’ll get lower temp overall.

Caster June 23rd, 2012

My colleague recently suggested patching out the reboot code from the kernel, as the hardware throttling should prevent damage anyway.Since my laptop fan died completely, I’m waiting for a new one and didn’t try it, but he uses it just fine.

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