Tired of the hum? I hear you. Thinkfan lets you silence a ThinkPad laptop in Plan 9. The inspiration came from the identically named Linux program.
The program is dead simple. Run thinkfan without arguments and it tells you the current fan speed. Give it a number in the 0 to 7 range, and it sets the fan speed accordingly. Zero means off, 7 indicates the maximum speed. That's all. I am relying on Intel to throttle the processor before it overheats. So far I haven't fried any chips. Your mileage may differ. I do run stats -z on my desktop and keep an eye on the temperature. When it approaches 100°C and the laptop slows down I increase the fan speed.
I have successfully tested this program on Lenovo ThinkPad models X220 and X230.
cp thinkfan /rc/bin/
echo thinkfan 1 >>/cfg/$sysname/termrc