• Welcome to Overclockers Forums! Join us to reply in threads, receive reduced ads, and to customize your site experience!

fan rpm question

Overclockers is supported by our readers. When you click a link to make a purchase, we may earn a commission. Learn More.

PG~LID

Registered
Joined
Mar 15, 2001
just wondering on how if a fan is a 2 wire set up...how do programs like mbm5.0 and others know the rpm's of the fans?....there are only 2 wires....i can see how a 3 wire hook up could send a reading through the third wire...but when you only have 2????? just wondering.
 

doublec16

Registered
Joined
Apr 3, 2001
If the fan is supplied with a constant voltage through 2 wires, the rotation speed is related to how much current the fan draws, which would be measured through those same 2 wires.
 

Gerti

Registered
Joined
Feb 18, 2001
The third usually yellow wire measures the RPM's of the fan.If u remove it or u have a two wire fan than say bye bye to monitoring the RPM's.