Sabertooth 990FX - Use of cha_fan1-4

[Nicolai]

Motherboard: Sabertooth 990FX

I have used all cha_fan1-4 for chassis fans, but what I see is that cha_fan1+4 is running slower than cha_fan2+3.

I have the following setup:
cha_fan1 (1320 rpm): Air in on 2xPCI-e cards from the side
cha_fan2 (2836 rpm): Air out through Rear
cha_fan3 (2689 rpm): Air out through Top
cha_fan4 (755 rpm): Air in on Harddrives through Front

The fans are more or less connected to the motherboard as they where closest to.

Am I wrong to see a problem in the two fans blowing air in running slower than the other two when they are actually cooling vital parts?

 

[David]

Hi, welcome to the forums!

Are all of the fans the exact same model? If not, the difference in RPM isn't as much of an issue because different fans move different amounts of air even at the same RPM.

 

[Nicolai]

Hi David, and Thank you

The fan cooling the Harddrives came with the Coolermaster Cabinet. And a week later I bought the 3 extra fans, also Coolermaster but not the same model.

The fan cooling the harddrives was connected to the PSU but i changed that to the motherboard instead as I thought it would be better as it would be controlled.

Is it so that some asus motherboards go slower in cha_fan1? And maybe the case that the fan on the harddrives just dont run more than that?

 

[Nicolai]

Ok, I did some testing on this. I swtched cha_fan1 and cha_fan2 and now the intake from the side is running with the 2836 rpm. It seems that cha_fan1 and maybe also cha_fan4 are set to run at a lower percentage.

I should aim for more intake than exhaust right?