I have a Lenovo T520, which is annoyingly loud all the time. My CPU however doesn't do anything and the BIOS is set to "balanced mode".
I tried to check, and the fan control is set to automatic, and even correctly tells the fan to run at low speeds or turn off:
root@xubuntu:~# cat /proc/acpi/ibm/fan status: enabled speed: 1974 level: auto root@xubuntu:~# cat /proc/acpi/ibm/fan status: enabled speed: 0 level: auto
However, my fan is ignoring that completely, running happily all the time on full speed despite having the
ondemand governor set:
tux@xubuntu:~$ cat /sys/devices/system/cpu/cpu0/cpufreq/scaling_governor ondemand