My ThinkPad W500 used to crash sometimes under heavy load because the automatic control is not speeding up the fan far enough. But I was able to disengage the fan and let it run at full speed in Ubuntu 10.10. But this does not work in my new nice and shiny Ubuntu 11.10. Have a glimpse at fan control device. % ls -l /proc/acpi/ibm/fan -rw-r--r-- 1 root root 0 2012-03-18 15:46 /proc/acpi/ibm/fan % cat /proc/acpi/ibm/fan status: enabled speed: 3056 level: auto Now become super user in a fresh and clean environment and send control sequence. % exec sudo env -i bash -l $ echo 'level disengaged' >/proc/acpi/ibm/fan bash: echo: write error: Invalid argument What did I miss? Thanks for suggests.