[dvdkon]

I think the thermal mass of typical desktop coolers is large enough that a smoothly tuned PID controller would fare well, without hindering performance or annoying the ueer.

I suppose the best way would be to try, but my current computers have no (or very unstable) interfaces for fan control.

[pstrateman]

Modern CPU coolers are basically heat pipes connected to a radiator.

They have very little thermal mass and if too much energy is in them the liquid all evaporates.

When the liquid evaporates their performance falls off a cliff.