Why won't my fan speed up?

Soldato
Joined
24 Feb 2003
Posts
3,142
Location
Porthcawl and Southampton
I have an Akasa AK966 "Blue Aurora" cooler on my Q6600.

Thought the temps were a bit high so I thought I'd do a bit of digging.

Turns out the fan never goes above 650rpm even though it should go up to 1500rpm.

I've tred changing every setting in the BIOS regarding power/clock/fan management but nothing has worked.

The mobo is a Gigabyte GA-P35-S3G.

Any suggestions?

edit:I don't have another 4 pin fan to try.
 
Last edited:
If you've put the CPU fan connection to the SysFan2 connection it only gets 5v. Maybe that? I'd be somewhat surprised if this is the case though as the CPU Fan is clearly labelled.

Anyway the only BIOS option would reside in PC Health Status with the option 'CPU Smart FAN Control'. Though if Disabled this should normally run to 12v until you use EasyTune software to dial it down (or speedfan which is even better)
 
Thanks for your reply

Definitely connected to the 4 pin CPU fan header. Also,the speed doesn't change when it's disabled. No matter what I do the speed is indicated as 650rpm and believe me it looks slow.

I've tried a 3pin fan and adjusted the speed with a rheostat and the fan speed indication in windows does change. It has also dropped my [email protected] from mid 60s to mid 50s under full load with ambient temp of 29c.
 
Maybe the fan is faulty? On my GB board I se to recall two options PWM and something like voltage. Did you try that?

I have a 3 pin connected to my 4 pin header and that works just fine, although Easytune didn't like it much but Speedfan is happy to dial them down for me.
 
I tried speedfan, it wouldn't change the speed. I've now got the CPU fan connected to the 4 pin header for "pwr fan" this is giving a much higher speed.

Bit confused by all this.
 
Are you able to regulate the speed on that header? Would be a shame to have it blowing shed loads of air all the time and making a racket.

I suppose you could always use a Zalman fanmate to find a sweet spot for airflow.

Something's not right though. CPU FAN should be 12v. If you have a multimeter I would try and check that voltage being presented to the fan to verify it.

Isn't the PSU FAN header a 3 pin one though?

Only CPU and Sys Fan 2 should be 4 pins. At least according to the manual anyway.
 
Thanks again for the reply, The cpu header is 4 pin. When I plug a 3 pin in there the fan has plenty of juice and spins nicely. When I plug the fan that came with the cooler into a 3 pin socket it spins up nicely too.

I think I'm just going to leave it as an unexplained quirk and workround it by using a fan controller or just leaving the cpu fan plugged into a different header.

P.S. You're right the "pwr fan" is 3 pin.
 
Back
Top Bottom