Loud fan noise using OS 9 (G4 MDD)

[Nova77]

Ok, we all know G4 MDDs aren't the most silent machines...
But why do the fans run twice as fast when I'm using OS 9 (compared to OS 10.5)??
Any way to fix this?
Thanks!

 

[ThunderSnake]

Ok, we all know G4 MDDs aren't the most silent machines...
But why do the fans run twice as fast when I'm using OS 9 (compared to OS 10.5)??
Any way to fix this?
Thanks!

What firmware do you have installed? In OS9, fan speed is controlled by firmware instead of software.

More info.

Also, if you're running CHUD nap mode in Leopard, OS9 is probably running hotter even at idle (than you normally run in Leopard) and kicking the fans up higher.

 

[Nova77]

What firmware do you have installed? In OS9, fan speed is controlled by firmware instead of software.

More info.

Also, if you're running CHUD nap mode in Leopard, OS9 is probably running hotter even at idle (than you normally run in Leopard) and kicking the fans up higher.

I'm not using CHUD nap mode. Fans turn X2 speed even at start under OS 9, and don't tell me the CPU is already hot loll...