[ltp] Fan speed in disengaged mode

[Michael Karcher]

Am Dienstag, den 15.01.2008, 12:10 +0200 schrieb Mihai C=C4=83lin Bazon:
> I had a serious thermal problem with my laptop, that is,
> temperature was around 70-80=C2=B0C even when the CPU was idle, with
> fan in "disengaged mode" [1] (/proc/acpi/ibm/fan reported fan
> was running at 5800 RPM).

> However, I noticed that in "disengaged mode", the fan only
> reaches 4500 RPM now (compared to 5800 before cleaning).  Could
> I have done something wrong that possibly damaged the fan?

Probably everything is fine. Is disengaged mode, the fan speed is
unregulated. If the airflow is blocked, an unregulated fan runs faster
than if there is airflow, because accelerating the air takes momentum
out of the fan.

If you are brave, you could cover the ventilation holes of your computer
(if possible) with your hand. The fan speed should go up, as the airflow
is now blocked again.

Regards,
  Michael Karcher