Re: dbcool on iBook G4 late 2004 doesn't work

[Paul Goyette <paul%whooppee.com@localhost>]

On Sat, 11 Oct 2008, Michael wrote:

> > Also, I would expect the fans to run at full speed until you've used the 
> > various sysctl(8) variables to tune the PWM algorithm.  See 'sysctl 
> > hw.dbcool' and 'man 4 dbcool' for description of the sysctl stuff.
>
> Umm, no. The iBook's firmware programs reasonable temperature thresholds into 
> the chip ( IIRC 85C for the CPU, lower values for RAM and GPU temperature ) 
> so the fans should most definitely /not/ run at full speed on startup. On the 
> other hand, since we upgraded to gcc4 starting the Xserver apparently heats 
> up the CPU quite a bit so the fan speeds up but it should slow down again. 
> This effect is probably exaggerated on my iBook though, I set the CPU 
> temperature threshold to 75C.

Ah, wonderful!  I wish the x86 BIOS/motherboard folks would initialize 
the sensors to sane values!  (Maybe I should migrate from amd64 machines 
to an iBook?)


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