[ltp] Re: tpfand configuration for an X200s

[Henrique de Moraes Holschuh]

On Sun, 07 Dec 2008, Christoph Bier wrote:
> Henrique de Moraes Holschuh schrieb am 07.12.2008 11:43:
> > On Sun, 07 Dec 2008, Christoph Bier wrote:
> >> Yes. But under Linux the fan is running at temperatures at which
> >> (right grammar?) the fan is not running under Vista. I would
> > 
> > I'd like a confirmation of that: a snapshot of the fan RPM and all thermal
> > sensors in both Windows and Linux, showing a set of thermal readings that
> > are almost the same, and the different fan speeds.
> 
> Thanks for your persistency! I did some testing and found that even
> under Linux the fan stops below certain temperatures (see [1]). But
> I can only achieve that low temperatures with an external fan! And
> under Vista the fan stops at higher temperatures and sometimes runs
> at comparatively low temperatures ([2]--[7])---due to hysteresis?!.
> Actually Linux' power consumption and hysteresis seem to keep the
> fan running even following powertops suggestions, lowest backlight
> brightness and disabled WLAN, Bluetooth and WWAN. :-(

Well, now that Lenovo has told me they have advanced adaptative
thermal control drivers in Windows, there is no reason to NOT believe
they might be informing the EC that there is extra thermal control
intelligence in the O.S, and the EC can be more liberal in the fan
control (i.e. run the fan slower).  I don't have PROOF this is what is
happening, of course.  But it is likely.

-- 
  "One disk to rule them all, One disk to find them. One disk to bring
  them all and in the darkness grind them. In the Land of Redmond
  where the shadows lie." -- The Silicon Valley Tarot
  Henrique Holschuh