is it possible to control all case fans via pwm?

panyan · 28 May 2011 at 17:42

i really dont like noise and noisy fans, and i understand that the pwm fan header on a motherboard is controled via temperature sensors in the cpu

is there a way to control all the case fans in the computer (three fin case fans and 4 pin cpu fan) via this pwm header?

that would allow quite operation at idle and good cooling when under load

EDIT: is ther a fan controller that can take the pwm and distribute that to the other 3-pin case fans?

lrlcr · 28 May 2011 at 17:47

you can get 1 -> 6 3pin splitters.

Personally I'd just get a fan controller though as that may well be too much load for one header.

Tealc · 28 May 2011 at 17:54

If your case fans are PWM controlled (4 pin jobbies) then you could buy a number of PWM splitters to do the job. If they are 3 pin fans then you'll need to control them using other means. 3 pin fans are not controllable by PWM signals unless you get into electronics and convert the PWM signal to DC.

panyan · 28 May 2011 at 18:03

Tealc said:
If your case fans are PWM controlled (4 pin jobbies) then you could buy a number of PWM splitters to do the job. If they are 3 pin fans then you'll need to control them using other means. 3 pin fans are not controllable by PWM signals unless you get into electronics and convert the PWM signal to DC.

understood, have edited OP

Phenomenologica · 28 May 2011 at 18:33

If you have PWM you don't want a manual fan controller as well, that won't work.You want a fan controller for 3 pin fans or a PWM splitter cable or two for four pin automated fans. The Akasa PWM splitter works but is a mess of cables, you may want to fork out on a braided one. Just google PWM splitter and you'll find some options.

Reaper 392 · 28 May 2011 at 19:22

one of these should sort you out nicely:

http://www.overclockers.co.uk/showproduct.php?prodid=CB-031-AK&groupid=1929&catid=153&subcat=

lets you have 3 fans plugged into the CPU fan power managing socket, and takes power from a 4 pin molex connector on your PSU.

with the 4 pin molex supplying the power, you could probably get away with some fan splitters to go along with it if you needed more than 3 fans to be controlled

*edit*
you may need some adapters for it too. im not sure if this is for 3 or 4 pin fans

Tealc · 28 May 2011 at 19:25

I don't think theres a solution off the shelf for this. Some fan controllers can control PWM fans but they dont usually receive and broadcast a signal.

Look into a fan controller to control your case fans or swap them all for 4 pin fans such as the akasa apache.

23JMZ07 · 28 May 2011 at 20:39

Sunbeam bought out their "rheosmart" for exactly this reason

It takes the 4pin PWM signal from the motherboard and controls up to 6 normal 3 pin fans via that signal. It works just like a normal fan controller too if you dont want to use the PWM mode.

Finding one in the UK though is the challenge

http://www.sunbeamtech.com/PRODUCTS/Rheosmart/6.html

panyan · 28 May 2011 at 21:49

23JMZ07 said:
Sunbeam bought out their "rheosmart" for exactly this reason

It takes the 4pin PWM signal from the motherboard and controls up to 6 normal 3 pin fans via that signal. It works just like a normal fan controller too if you dont want to use the PWM mode.

Finding one in the UK though is the challenge

http://www.sunbeamtech.com/PRODUCTS/Rheosmart/6.html

now THAT is what i am talking about!

i just hope i can find a UK distributor...

Admetos · 28 May 2011 at 22:09

Very related to the OP's thread, I'm would like to-do something very similar.

I have the following standard fans in a Silverstone Raven Case.
3x180mm (regular 3 pin)
1x120mm (regular 3 pin)

I have a Gigabyte P55M-UD2 board
http://www.gigabyte.com/products/product-page.aspx?pid=3287

Currently I have the 1x120mm controlled directly from the system fan header, speed fan reports RPM, and speed increases as temperate increases. I would like to have the 3 bottom fans controlled this way also.

Now the system fan header is 4 pin, and always presumed it was PWM, however the 120mm fan is a regular 3 pin fan that came with the case. I'm now confused if the system fan header is regular type or PWM now?

I did consider using a cheap 3 pin fan splitter, to power all 4 fans, however released it may overload the fan header.

Any input on solution to above appreciated.
Cheers
Jason

23JMZ07 · 28 May 2011 at 22:12

The header is PWM capable but it is controlling the speed using voltage regulation at the moment instead. The headers usually can take 1.5 amps which shouldnt be a problem with 3 standard case fans

Just use a 3 way splitter (of course only 1 fan can be RPM monitored)

Admetos · 28 May 2011 at 22:26

Thanks for explanation on the PWM using voltage regulation at the moment.

The bottom 3 fans are the following, are you sure these won't overload motherboard. I can't find any amps for them.
http://www.silverstonetek.com/products/p_contents.php?pno=AP181&area=usa

I may disconnect the single 120mm at the top, and just use 3 above. Also when using motherboard fan header, is it still safe to use a resister/controller to control speed. Thats if motherboard sets speed to high once temps increase.

23JMZ07 · 28 May 2011 at 22:36

JUST using them 3 fans might be fine. They are 0.45 amps each so they total 1.35 amps. The headers usually are capable of 1.5 amps however some are only 1 amp. I think you may be on the danger side of things with those fans. You may be better off just using a fan controller or spreading the load amongst more than 1 header. You can use resistors / controllers on the fan headers yes.

Admetos · 29 May 2011 at 11:18

I believe the Gigabyte board gives 1.5amp, as you say should just be ok.

However if I used a resistance from the fan header, for sake of argument say it halved the fan amps (down to 0.22). Would this be equivalent as halving total load on the fan header, or would the resister still create load.

Cheers