[ltp] [ACPI] fan always on: ACPI on IBM ThinkPad R51 (searching for T41)

[Jonas Schirmer]

Hello list,

T41p, Debian Sarge, linux-2.6.8-1, fglrx here.

 Suso Baleato wrote:
>With powernowd and DynamicClocks activated in Linux, the fan behaviour is
>exactly the same between the two configurations. Letting the machine AC
>on, while doing nothing or just typing, the result will be loops of
>aproximately fourteen minutes of silence followed by seven minutes of
>_anoying_ noise to dissipate four C degrees starting at 38 and stopping
>at 34 aproximately.

Check if the C3-States are used in /proc/acpi/processor/CPU/power. If
they aren't used, I'm getting approximatly the same behavior on my
machine. USB devices (among others) prevent the processor from entering the
C3-State. If C3 is used the fan stays off, after a very long time to
cool off.

>Of course this is still a lot of noise, and the fan will not stop if
>doing any other thing than just watching -without touching- the ThinkPad
>design. So if you have a low-tolerance to noise, please *don't buy*
>this machine because IBM will say this noise is a feature. I can't
>imagine BMW saying that a always-on car engine fan is a feature...
>perhaps the correct name might be ThinkFan.
>
>So unless IBM solves the problem, this machine might be considered as a
>low quality one and blacklisted by those reasons. I will ask them for a
>way to replace it by another one that works as expected, but I don't
>know wich one. I found T41 as a possible option; any experience here?
>Does the fan works ok in T41?

Yes. The fan in the T41p is very quiet. Booting the machine cold,
reading an ebook for hours is possible without any fan noise. The non-p
variants are perhaps different in this aspect, though.


Jonas