PWM Fan Control Question

[rarebear]

I just bought 4 80mm PWMs

And I am planning to buy a Asus P5Q Deluxe

It had one CPU 4 pin header and four 3 pin headers

Will the Mobos these days tell the four extra PWMs to speed up or will I need to make a jumpers for the fourth pin to the CPU fouth pin?????



Also what speed does a PWM run at with just a 3 Pin plug???????

Last if I can make the jumper is there any danger to Mobo or Fans due to voltage..
Each pin can deliver 24 watts

but what does the fouth pin due???????
Send a signal or send more voltage?????????


Thanks I sorry I have been out of the Scene for a few years and everything is different AGAIN

 

[zerogear]

There should be BIOS settings to tell your fan to run at PWM. Usually BIOS nowadays should let you switch between PWM or voltage regulation (3-pin) to change fan speed. 4th wire consists of the PWM line, so its responsible for telling your fan to speed up or slow down.

While 3-pin regulation is upping or lowering voltage. So, use voltage if your fan is 3-pin, use PWM is its 4pin.

 

[Zepper]

Wondering why anyone would be buying 80mm fans these days?

.bh.

 

[rarebear]

Hi Zepper,
I have an old Antec case I am modding..

I thought about installing 120s but though I did not want to do crazy with fans..

I would like to get all the fans to work off the PWM has any one posted any threads on this???

When I built my first case most of the fans I bought where 30 db and I am replacing them with Arctic Cooling Arctic Fan 8 PWM

They have the wiring to piggy back connections but I dont want wiring running for the front and back of case..

I guess I have to test running the PWM 4th wire to the CPW header as the MoBo only has one 4pin header

 

[Zepper]

Well, only the 4-pin fan headers (usually CPU) can control a PWM fan. The standard 3-pin headers except for CPU are generally not controlled. I don't think you'd want all the fans in a case to be controlled by CPU temp. There are fan controllers with temp sensors so you can have each fan controlled by their own temp. I'd think that would be a better way to go even though they add a few more wires - at least the wires aren't large diameter. PWM fans run at full speed on a non-pwm header unless the header is voltage controlled. Some mobos provide control on the non CPU headers, but usually only at the high end, so I suggest an add-on fan controller.

.bh.

 

[rarebear]

Thanks Zepper,

I have been reading up and trying to figuer this stuff all out and I appreciate your taking the time to help..

Arctic Coolings website says you can control all the fan off the bios

They have special tails that let you plug two fans together and daisy chain as many as you like..

The board I am looking at says it puts out 25watts per header..

I would build a custom wire harness but I am trying to figuer what wires control the fans from hi to low..

I am guessing if I plug one RPM (3rd wire) and not sure if I need all the PWM 4th wires jumpered together or not to get fans to change from hi to low..

Thanks Again

Check my thread on Arctic Cooling fans they are really first rate for the price....
Just make sure to get the standard case fan not the custom rubber mounted model as they can only be used to blow out..

 

[Zepper]

Yes, on some mobos you can control fans other than the CPU, but usually just in one or two steps of your choice. Not very flexible IMO - that's why I use a stand-alone fan controller. A-C fans are decent but generally don't push much air - the C-M fans I use have ball bearings and can do about 100 CFM if needed - low-noise too at reduced RPMs. A-C's fans have ceramic bearings which are subject to shipping damage if not packed well - particularly when mounted in a case like their Silentium units. If they make it thru shipping in good shape, then you'll have a nice low-noise fan. With normal 3-pin fans, only voltage control is possible and that is best done on the red (12V pos) lead. Could be done on the black lead as well, but that shifts the ground base and can throw the speed sensor off as it is supposed to be referenced to true ground. Only one speed sensor wire can be connected to one header. The others need to be disconnected in some way.

.bh.

 

[rarebear]

Hi Zepper,

Thanks Again for your comments..

Do you or Anyone else know what the 4th PWM wire does??

I mean does it add more voltage or or trigger the fan to change speeds???

I am trying to figure how I can run power to the fand not off the MoBo and using jumpers to trigger my fans with temps of the CPU..

I am trying to avoid buying more hardware like the fan controller..

Also how much $$ do you have to spend to get a smart fan controller??
And is there any that can use a probe or wire to trigger fans..
Also do the controllers work of case temps and are they adjustable or is it just little resistor thingy at a fixed temp..

Thanks Again I am sure this has been asked and answered I just can find what I am looking for in the old threads..