slow fan speed with motherboard 3 pin

[faye]

Hi all,

I have a Asus A8N-SLI.
everything is at stock setting.

When i connect the cpu fan onto the motherboard cpu fan plug, the speed from Asus Probe say it is 1500rpm and if i use a convertor, connect it to a harddrive (4pin) power connector, it rated 5000rpm.

Can i change the speed of the CPU fan in the motherboard?
Also, there is a "chasis fan" plug for case fan , it is also a 3 pin, i put the 12mm coolermaster fan onto it, it says 1500rpm too, but if i connected with big 4 pin, it is 5000rpm.

Can i also change that speed from the motherboard or bios?

Thanks

 

[FireTech]

Where does it say it's 5000rpm? If you're connecting it to a molex plug, how is it reading RPM?
1500rpm sounds right for a 120mm fan, 5000rpm does not. I think your getting mis-readings from the way you're connecting it, you shouldn't have it connected to a molex plug AND the MB plug at the same time...
If it was running 5000rpm you'd know about it from the noise and windblast!
To control the fan speed from the MB connectors:-
Have a look and see if Q-Fan Controller is enabled. Around page 4-38 of your MB manual I think.
Also have a look and see if Cool and Quiet is enabled. Page 5-42 of your manual?

 

[Heidfirst]

As Firetech said.
CoolerMaster don't do any 120m fans raed at 5000rpm.

However, Asus boards do have QFan fan control so you might want to investigate that.

 

[faye]

ok...
i will read the manual now...

what is the "Cool and Quiet: anyways, what does it do?
should i keep it enable?

 

[FireTech]

It's AMD's utility which basically reduces CPU voltage when the CPU is idle, which reduces CPU speed, which reduces heat output, which reduces CPU fan speed (usually). There is a more technical (unlike mine) explanation on AMD's site

 

[Peter]

C&Q enables operating systems to control CPU speed. If you chose a power management scheme that actually uses it (Windows: "Minimal Power Management" for desktops; Linux: "Dynamic" CPU power scheme), then CPU speed follows CPU load.

Some boards control the CPU fan speed by CPU temperature - thus, a slow fan is a secondary effect of a powersaving CPU.