PWM problem

[brunello]

Hi to everyone!
I've followed this forum for a while, and I must admit it's great!

Now, I have a problem with my motherboard, an Asus P8P67-M Pro

I've recently changed all the fans in my case with PWM fans, I thought that, since I keep the system on my desk, that will give me good control over noise.

The problem is that I've problem with the PWM control, I mean, the Asus Utility (FanXpert) is incredibly slow to change the rpm, and the rpm fluctuate almost for no reason, sometimes the cpu fan remain stuck at idle speed even if the cpu temp goes up.

There are possibilities to use other programs? because in windows 7 everything was great, but I don't want to downgrade from w8.1

I had some trouble with SpeedFan, so if possible I prefer avoid it.

Hope to have choose the right section! Thanks!

 

[Jetster]

Set them in the BIOS. Should be a number to set them at and still fluctuate with the temp

 

[brunello]

The problem is that if I set the fan profile in the BIOS the fans have a very high idle speed, something like 900-1000 rpm, I don't know why because I set the minimum rpm as low as possible, using FanXpert on the other hand gives me the ability to set the idle speed as low as 350-400 rpm, dead silent.

P.S. I've the latest BIOS, I'm quite tired of this because I often leave the system on all night, and now I even consider to buy a new board just for this problem.

 

[Jetster]

And this is why they make fan controllers

 

[brunello]

yes, I know, but I choose PWM fan because I don't wanna mess with fan controllers, and because I prefer the fans adjusted by the board

Now I'm trying FanXpert 2 (for the 7x series boards) the cpu fan works good, the problem is with the chassis fans because I don't have independent channels for each connector.

Anyway, is it possible to use 4pin fan on a fan controller with 3 pin connector? I think the fan will work just as a standard voltage controlled 3pin fan.

 

[Jetster]

Anyway, is it possible to use 4pin fan on a fan controller with 3 pin connector?

Yes, you can put a 4 pin plug on the three pin and vice versa. The reason I brought up fan controllers is that motherboards are historically bad at controlling fan speed. With or without the software that is included with the motherboard. At full speeds they tend to starve the fans of voltage. And at slow speed they a inconsistent. A good fan controller provides the power and takes the job off the board so it has the power to do the other jobs. Its a win win. Board controller are not even close to the ability of a good fan controller. I don't care what board it is

 

[micropage7]

Yes, you can put a 4 pin plug on the three pin and vice versa. The reason I brought up fan controllers is that motherboards are historically bad at controlling fan speed. With or without the software that is included with the motherboard. At full speeds they tend to starve the fans of voltage. And at slow speed they a inconsistent. A good fan controller provides the power and takes the job off the board so it has the power to do the other jobs. Its a win win. Board controller are not even close to the ability of a good fan controller. I don't care what board it is

i never use pwm, just using molex and thats fine
if the noise is too much you can use better fans would help to reduce noise

 

[brunello]

I've just bought some very silent fan, a Noctua NF-f12 and two Scythe, one 120mm and a 140mm both PWM and low speed version.

from what you've said the problem is that the board's controller is not able to provide decent voltage regulation to those fan, that's pretty bad, considering what Asus advertise about FanXpert and the possibility of a "granular" control of your fans...

Now I think that I need to revise the flows in my system, I don't wanna add another fan but the temp with the 280x are getting quite high, and we're only in middle march... There's a section for cooling?

EDIT : I've found this, it seems that it uses the pwm signal from the cpu fan header to run the fan connected, am I wrong? because it'll be perfect for me, and it's also cheap and available in my country (Italy)

http://www.zalman.com/global/product/Product_Read.php?Idx=376

 

[Aquinus]

Where are you plugging these fans in? PWM fans can run on just voltage. It appears to me that your motherboard only has three 4-pin fan headers, two both are off the CPU fan speed (since one is an aux cpu fan, the other is the primary,) and the chassis fan header. I see a third power fan header, but that's 3 pin.

Where are you plugging in all the fans?

I personally have no issues with FanXpert, but I'm also only using voltage control and no PWM, even though every fan header on my board is 4-pin.

 

[brunello]

Yes, my board has only 3 PWM headers, now I have only 3 fans, cpu fan included, so all fans are connected to pwm headers, I also have another pwm 120mm that I use with an Y connector.

Now my target is a quite silent system for study/movies, and good temperature in gaming, another problem is that the gpu blow hot air just in front of the cpu fan, and the circulation in my case is not very good I think because simply temoving the side panel the temps drop by 4-5°C on the gpu a some degrees on the cpu too.

 

[Aquinus]

Yes, my board has only 3 PWM headers, now I have only 3 fans, cpu fan included, so all fans are connected to pwm headers, I also have another pwm 120mm that I use with an Y connector.

Which connector is that Y connector on? Is that just PWM or is it sharing power too? If it's sharing power, that could potentially explain a lot. Additionally, it's not on the CPU_AUX header is it? I find that the speed of the aux cpu fan is directly tied to the primary cpu fan header. So if your CPU fan on the primary CPU header is going slow, whatever is on the AUX header will also go relatively slow because the PWM output for each of them should be identical.