Rockpro64 CPU fan

[hunderteins]

The fan does not run very fast even at full speed.   It is a 12v fan.  I didn't measure the voltage powering it, I suspect it only gets 5 volts even at max speed.

I have a similar setup with a 12v case fan. But I can not confirm, that it perform always so poor. Basically there are three states at "full speed (echo 255)"

(1) I need to give that thing a manual kick start and than it spins slowly, cpu temperature is not affected
(2) it starts and runs slowly, the cpu temperature sinks about 5 °C
(3) it starts and runs really at full speed, so that I need to reduce it to echo 160, even than, the cpu temperature is seldom over 40 °C

I can't predict how this PWM-fan will behave.