[ltp] Fan Setup

[Richard Neill]

Nils Faerber wrote:
> Lior Uzan schrieb:
>> Hey all,
>> I have a T61. How do i keep the fan running all the time instead of only
>> when my pc passes a certain temp? (I don't remember if it was 50 or 52
>> celsius)
>> I don't like my CPU's temperature spiking whenever there's heavy load...
>> I passed the thinkpad_acpi driver the control_fan=1 option, now what?
> 
> Look into /proc/acpi/ibm and do e.g.
> 	cat fan
> 
> You can set the level then (like on. off. auto), like
> 	echo "level 0" > fan
> or
> 	echo "auto" > fan
> or
> 	echo "level 1" > fan
> 	(lowest speed)
> 
> But be careful. If you manually set the level then the auto function is
> disabled, i.e. if you set it to the lowest speed it will stay there
> regardless of how hot your CPU gets.
> 
>> Alternately, how do i lower the temperature that the fan starts at?
> 
> Pitily those AFAIK cannot be controled.
> 


See also thinkwiki.org  for some fan-control scripts.

Actually, 52 degrees is rather conservative - you could quite safely let
it reach 70 without hurting the chip. The low temperature is to prevent
it burning your knees!

If you have the CPU power-management set up right, you should be able to
enjoy near silent operation, yet without any sacrifice in performance.
This is because a typical "desktop" load requires 100% for a few seconds
at a time (eg when you open an application), then goes to near quiescent
for the next minute (eg when you are typing). The fan should only
activate when the system is seriously busy, eg updatedb, backups,
cron-jobs, huge file-transfers,..


HTH,

Richard