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



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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