What determines the RPM of a T60 fan?

[propellen]

I'm controlling my fan with TPFanControl, and I love it
When the fan is not off it goes off on level 1 = minimum = 2980 RPM.

BUT, in search of perfection I'm wondering if it would be possible to write a program to set a fixed speed, ex. 2000rpms ? Has the RPM something to do with the physical design voltage requirement of the fan?

What determines the min and max rpm values of the t60 fan?

[agarza]

I think the fan RPM's values are hardcoded in the BIOS Embedded Controller, you cannot change those. Use TPFancontrol to set a fixed speed of 1 regardless of the CPU temp.

As a matter of fact I've never seen my T61 fan ramp up to 3500rpm.