Performance drops when fan speeds up?

[computerpro3]

I am having a strange problem on my new t61. I am playing counterstrike source, which runs great (60-100fps). Maybe every twenty seconds or so, the fan spins up to deal with the increased heat. When this happens, my FPS drops to 10. When the fan finishes spinning up, it goes back up to 100. Then another ten seconds later, the fan spins down, once again dropping my framerates.

It does not do this with other games.

Any idea what is going on?

[meekus]

Intel's SpeedStep tech allows for the automatic underclocking of the CPU to reduce core temperatures.

Check to see if the AC power settings in the Power Manager are not set to anything other than:

Maximum CPU speed = Highest
Optimize fan control to = Maximized performance