There’s just one minor annoyance with my new LibreBoot Thinkpad X60 from GLUGLUG. Working it hard causes it to overheat and shut down. Thankfully, the fan turns out to have much more capability than the defaults allow; all but solving this problem.

In Trisquel GNU/Linux 6.0, the X60′s automatic fan controller runs at one of eight preset speeds (0-7), depending on the temperature. About 10 mins with both CPUs running at 100% will cause it to overheat (eg. two copies of python -c"while True: pass").

As described on ThinkWiki, you can manually override the fan control by adding the line options thinkpad_acpi fan_control=1 to /etc/modprobe.d/thinkpad_acpi.conf. Then after rebooting and as root, you can set the fan to run at maximum speed (~3700 RPM) with:

echo level 7 > /proc/acpi/ibm/fan

Only that’s not the true maximum speed. You can actually disable the rotation speed regulation and just supply full voltage to the fan (~4900 RPM):

echo level full-speed > /proc/acpi/ibm/fan

This setting is a bit noisier, but allows both CPUs to run at 100% with no signs of overheating. A good result.

Next I need to figure out how figure out how to enable this automatically when the machine gets hot. I’ve tried thinkfan, but it seems to only allow the default 0-7 speeds used by the default fan control.