Comment 7 for bug 1019468

Gordon: about having the fans driven by the average temperature: this mode was implemented by Mikael in the very first versions of macfanctld (see http://ubuntuforums.org/archive/index.php/t-1467062.html). I'm pretty sure it's never used since CPU/GPU proximity temperatures (sensors TC0P and TG0P) are always higher than the average temperature.

About CPU/GPU die temperatures spiking very fast (sensors TC0D and TG0D): yes, and this is why Mikael decided on using the proximity temperature sensors instead (see same forum thread). Using sensors that are not directly on the die allow for the temperature spikes to be naturally filtered out.