[ltp] ThinkPad T520 fan: less rpm recently

[Martin Steigerwald]

Am Freitag, 2. September 2011 schrieb Martin Steigerwald:
> Hi!
>=20
> One of the few things that annoyed with the T520 was the fan noise when
> using it with Linux. I got about 2640 rpm, sometimes even 2800 rpm.
>=20
> Well I don=B4t know what changed, but it got better and it was not:
[... fan at 1950-2000rpm ...]

Now I added an option which - for the first time - let the fan be switched=
=20
off automatically for short whiles:


Every 1,0s: cat /proc/acpi/ibm/fan             Fri Oct 14 23:52:08 2011

status:         enabled
speed:          1950
level:          auto

Every 1,0s: cat /proc/acpi/ibm/fan             Fri Oct 14 23:52:43 2011

status:         enabled
speed:          0
level:          auto


from /etc/default/grub:

GRUB_CMDLINE_LINUX_DEFAULT=3D"pcie_aspm=3Dforce i915.i915_enable_rc6=3D1=20
threadirqs"

except for "threadirqs" - just for playing around, seems to have no=20
influence on fan speed - I added "i915.i915_enable_rc6=3D1" after I read:

Thorsten Leemhuis, Die Woche: Ungenutztes Stromsparpotenzial
http://www.heise.de/open/artikel/Die-Woche-Ungenutztes-
Stromsparpotenzial-1361381.html

It does not seem to be online in an english translation at H Open yet.

I will now test whether my T520 will work stably with that option. And on=20
the train on Sunday I will see what this does to the battery life!

Thanks,
=2D-=20
Martin 'Helios' Steigerwald - http://www.Lichtvoll.de
GPG: 03B0 0D6C 0040 0710 4AFA  B82F 991B EAAC A599 84C7