[ltp] Noisy fan on T42

[Konstantin Filtschew]

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hi,

Linux doesn't control the fan, it's the ibm bios, which control the fan.
We try only to reduce the temperature through bios, so the bios stops
the fan, thats the problem. Controlling the fan is still not possible
for T40 and later as far as I know.


Greetz

Konstantin



On Mon, 14 Mar 2005 10:36:45 -0500
"Alexandru D. Salcianu" <salcianu@MIT.EDU> wrote:

>=20
> Hello!
>=20
> I checked the CPU speed by looking into /proc/cpuinfo (I will try your
> method too).  As expected, the CPU speed stays at 600Mhz most of the
> time, and goes up only when I do something serious.  I don't think the
> CPU frequency or the CPU temperature is the issue: as indicated by
> ibm_acpi, the CPU temperature (the first of the 8 reported
> temperatures) is quite small: 40-42C
>=20
> I think one of the following situations takes place:
>=20
> 1) the temperature indications from ibm_acpi are incorrect;
>=20
> 2) there is some other source of heat (unlikely: I've tried laptop
>    mode to decrease the heat generated by the HDD; I've even booted
>    the system in text mode to avoid the GPU generated heat; also, when
>    I ran X, the radeon driver has the dynamic frequency scaling
>    enabled);
>=20
> 3) somehow, linux doesn't realize that the temperature is low and it
>    should stop the fan (once the fan goes full power - pretty soon
>    after booting - it *never* comes back to a slow speed, and it
>    definitely never stops)
>=20
> Best,
>=20
> Alex
>=20
> > > It looks to me that current power management tools in Linux simply
> > > cannot handle my laptop (the fan noise is acceptable in Windows,
> > > although things can be improved a bit there too).  I'm looking
forward
> > > to trying the next versions of acpi and ibm_acpi.
> > Have you verified that your processor is not running at full speed
by
> > loading the speedstep_centrinom module and looking in
> > /sys/devices/system/cpu/cpu0/cpufreq/cpuinfo_cur_freq ?  I'm not
sure the
> > BIOS settings work in Linux, my fan was running almost all the time
but once
> > I loaded speedstep_centrino and cpufreq_ondemand and ran this:
> >=20
> > ---=3D=3D=3D
> > #!/bin/sh
> >=20
> > DIR=3D/sys/devices/system/cpu/cpu0/cpufreq
> >=20
> > echo -n Enabling on-demand CPU frequency governor...
> > echo ondemand > $DIR/scaling_governor
> > cat $DIR/cpuinfo_min_freq > $DIR/scaling_min_freq
> > cat $DIR/cpuinfo_max_freq > $DIR/scaling_max_freq
> > echo done
> > =3D=3D=3D---
> >=20
> > the fan only comes on occasionally now and is quieter when it does
come on.
> >=20
> > --=20
>=20
> --=20
> The linux-thinkpad mailing list home page is at:
> http://mailman.linux-thinkpad.org/mailman/listinfo/linux-thinkpad


----------------------------=20
Building an operation system without source code,
is like buying a  self assemble space shuttle without
instructions.

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