Cpu Fan Speed Very Odd Thing?

[angel_of_death57]

Right i had my stealth 120mm intake fan with 52CFM on it but now replaced with a 120mm 125CFM fan now with the 52 CFM my CPU fan speed would settle idle at around 1600RPM but now i got the 125CFM now its gone to around 1700. Before i got any intakes it was at this speed. Maye its voltages orsomething i am not sure the 52CFM fan had a 3 pin connector with adaptor to 4 pin i used my new 125CFM just is 4 pin if that makes any difference.

Any ideas what happened

[tesco]

is the cpu temp hotter now? or cooler? try using speedfan to make the cpu fan run slower.

[angel_of_death57]

Originally posted by ROSSCO_2004@16 August 2004 - 15:52
is the cpu temp hotter now? or cooler? try using speedfan to make the cpu fan run slower.
nothing like that Rossco i am just wondering why the speed changed the temps about the same in this hot weather very odd though. In BIOS Cpu fan set at 50'C Tolerance 5 which workswell for me

[lynx]

The same voltage or pulse width on two different fans will produce different rotational speeds, it is just a factor of the fan design. Even if the fans are the same make and model you could easily get the variation you have described.

While the system will report the rotational speed it does not try to achieve a constant speed because of the very fact that different fans have different airflow characteristics, something it cannot measure.

[angel_of_death57]

Ah right well i did change my intake fan onto a different rail i was on Hard drive > Exhuast Fan > Intake now its on DVD-Rom > DVD RW > Intake fan

The CPU fan powered from mobo and mobo connected up with 20 pin and the 4 pin for the fan.