D975BXB2, Fan control, Clicking

[Bookseller]

Built a normal, not oc E6600 on D975BXB2 and have one annoying problem.

At anything other than 0 or 100% fan speed for the front and rear fan (no third fan connected), when the fans are driven off the motherboard, there is a significant clicking noise.

I am certain it is from the fans, I have disconnected and reconnected and it goes away. With only one fan it is present but quieter.

This is NOT from the processor fan, but from the case fans. If driven direct off a power supply as opposed to the motherboard there is no clicking.

If controlled from the IDCC at 0% or 100% there is no clicking, anywhere in between it occurs.

These are generic cheap fans the store gave me, but did have the three wire connectors for the board.

The other observation is that the IDU and IDCC both show the RPM varying wildly when they are running at anything but 100%, as though it lacks appropriate control, maybe cycling too fast or two slow on some kind of power control. It's not something as silly as a mechanical relay to control these is it?

Anyone else have this?

2/16/2007 version of the bios.

PS. Everything works fine, just I hate choosing between hot, noisy clicks, and noisy fans.

[progrip]

Try them in another comp to make sure its the mobo and not the fans.

If that doesnt work and its the mobo that's the problem, I would just buy better (name brand) fans.

[BlackRebel]

yep, this happened to me too. i'm assuming its has something to do with reduced voltage and the fans ability to operate in such a state. of the case fans i tried, a 92mm panaflo, 92mm apc and a 80mm coolermaster only an arctic cooling af8 operated at reduced rpm without pulsating. so, i run 2 80mm coolermasters off a feed from the psu (quiet but little oomph) fot intake, the AC out the back (quiet also) and then i'll need one more 92mm intake when the weather warms up. i'll likely try the evercool pwm fan.

[Bookseller]

yep, this happened to me too. .... only an arctic cooling af8 operated at reduced rpm without pulsating.

Interesting, so you think it is the fan itself making the noise in response to the motherboard changing the voltage?

I was thinking about this overnight. Both in the bios hw management display and in the IDCC it shows wildly varying fan speed when it is anywhere between 0% and 100%. Varying more than is physically posisble (inertia and all that).

I was wondering if that is a cause or an effect. Is that supposed to be a sensor on the fan measuring (counting) actual RPMs? If the board's ability to sense rpm is flakey that could account for its output voltage (driven by some algorithm from the input sensor) varying wildly as well. Though at full speed I get a steady RPM count off of it.

Anyway... anyone have a motherboard controlled 120mm fan running at variable speed without clicking? Brand/type?

[Sparky]

I'm using 2 Antec Tri-Cool 120mm with no problems. Only thing I've noticed is that the LED on fans "strobes" due to mobo controlling fan speed. Both fans are set on high thus allwoing mobo to fully control speed.

http://www.newegg.com/Product/Product.a ... 6835209011

[rocktrout]

I've encountered this a few times on my system with the fans supplied in my Thermaltake case. At first I thought it was one of my new HDs going bad. I may try swapping out those Antec fans in the near future.

Another thing I've noticed is this tends to occur when I have SpeedFan running. I'm going to run all day with SpeedFan off and see if that makes any difference one way or another.

[BlackRebel]

Interesting, so you think it is the fan itself making the noise in response to the motherboard changing the voltage?

yes and no! i concluded it was the psu making the noise, however as i tested the variety of fans i had by holding them while plugged into the mb i could feel the "sound" in my palm. my voltage conclusion, it's based on a years ago tech support forum thread where the complaint was that a particular fan could'nt be under volted without it making alot of noise. that seems to be the case with the fans i have. in any case, i think what's needed is a pwm fan or like the tri-cool mentioned above, a variable speed fan.

[gara56]

I recently started having the same problem with one of my Lian Li case fans. I think it's the rear fan. I didn't have this problem when I had my other Intel board (D975XBX) was installed. I noticed that the fans run a little slower on the XBX2 than the old XBX. I also believe there were some changes made to the bios to make sure the fan speeds increased as the CPU/MOB temps went up. Believe they did this to satisfy complaints that many people had with fan noise coming from the case. When I increase the speed of the fan, the clicking goes away. I just don't think some of the case fans were built to run that slow. I'm in the process of replacing that fan with another just to do a test.

Glenn

[vddobrev]

My first post - long time reader though.
When I was building my system based on XBX2, I went thru a lot of fans because of the "clicking". The fans needs to be able to operate under low voltage (starting voltage), or in other words has additional circuitry called "speed sensing". I have discovered such fans:
Vantec Stealth Series - purchased from newegg:
60mm http://www.newegg.com/Product/Product.a ... 6811999601
80mm - http://www.newegg.com/Product/Product.a ... 6811999602
92mm - http://www.newegg.com/Product/Product.a ... 6811999603
120mm - http://www.newegg.com/Product/Product.a ... 6811999614

In my system, these fans (2x80mm + 2x92mm) do not click, and are whisper quiet.

[grsc3p0]

The clicking fan noise is caused by the PWM fan controller.
Pulse Width Modulation is a method of applying a signal to the fan that will vary the width of the fan's pulse. e.g. fan control is digital.

Some fans tend to click with PWM controllers and some don't.
Had to replace my Panaflow fan with a Noctua which seems to be compatible.

Google 'PWM fan' for more info on the subject.
The problem is trying to find PWM compatible fans!