Re: How does one control fans?
Koen Vermeer said...
> On Wed, 2005-10-12 at 23:08 +0100, marc wrote:
> > I'm gradually inching my way to total control of my laptop, but now I
> > would like a bit of peace and quiet every now and then. In XPland, the
> > fan is more off than on, in Linux, it's rarely off at all.
> >
> > How do I start to get a grip on a peaceful Tux experience?
>
> I think it could be too things: Either the system is running too hot, or
> the fans kick in too soon.
Yup, I agree that those are the two scenarios.
> If your system is really running too hot (more so than when running XP),
> look at what process is taking CPU time.
It isn't this, because the air being expelled is barely discernibly
warmer than room temperature - and the room is quite cool.
> Or maybe you aren't using
> throttling, so the CPU is always running at full speed? In that case,
> enable CPU frequency scaling and make sure it runs with the right
> governor (probably 'conservative').
Ah, something else to explore. I installed the cpudyn package and that
stops the fan a little. However, reading man cpudyn, it mentions that
throttling is integrated into kernel from 2.6 on - I'm using 2.6.13.
When I removed it, and rebooted, the fan went back to never switching
off.
I noticed that a lot of folk use
# modprobe cpufreq_userspace
so I loaded that, which at least stops the fan from time to time,
although I have no idea what it does! (Despite goggling for a while...)
That said, it seemed to have created the /proc/acpi/processor/ chain.
Which modules and packages are the "best" too use, or to start with?
> Otherwise, maybe the thermal trip points are too low. Look
> at /proc/acpi/thermal_zone/THRM/temperature to determine the temperature
> according to the system.
I don't have /proc/acpi/thermal_zone/ :-(
> Then look
> at /proc/acpi/thermal_zone/THRM/trip_points to see the trip points. In
> my case, it shows something like
>
> critical (S5): 100 C
> passive: 92 C: blabla
> active[0]: 66 C: blabla
> active[1]: 63 C: blabla
>
> This means that at 63 degrees, the fan (FAN1) starts blowing, at 66
> degrees FAN0 also starts, at 92 degrees the system is throttled, and at
> 100 degrees it's turned off. Also, my current temperature is 42 degrees,
> and the fans are indeed turned off.
>
> For more information, look at
> http://acpi.sourceforge.net/documentation/thermal.html
Should I install acpi? I see a debian acpi package, but it appears to be
different to the stuff on that web-site.
I'm also on a hunt for the speedstep_centrino module, which bombs when I
try to load it. I'm guessing that this requires a kernel rebuild... but
who knows!
--
Best,
Marc
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