Anyone here tried a PWM fan splitter cable?

[DanceswithUnix]

My mini-itx system has only one fan header on the motherboard, thinking this aught to be possible a quick google turned up:

http://www.amazon.co.uk/Akasa-AK-CBF...=cm_cr_pr_pb_t

which looks like it might work for me.

I would expect you want a pair of well matched fans, preferably identical, so that they respond the same way to the same PWM signal as only one has the tacho sent back to the motherboard. I'm sure a PIC chip could slave one fan speed to another properly, and maybe someone out there does something like that as well, but this might be enough (though I might have to replace one fan to get a matched pair of the same model).

[Biscuit]

I have used similar things, but not that exact one. I have previously used:

http://www.scan.co.uk/products/45cm-...ia-4-pin-molex

But the old version before they braided it.

Its currently in my system working fine but its a bit messy so i have bought:

http://www.scan.co.uk/products/ek-ca...n-pwm-extended

Waiting to go in to replace it.

[Agent]

Going from the PSU is always a better bet. The fan headers on mobos usually get upset when you put too much current through them. Modern, large slower fans are unlikely to cause an issue, but I remember the days when people would hook multiple Delta fans to a single header and watch it fry

Biscuits suggestions look spot on

[DanceswithUnix]

This is in a small case, if I got the one with the molex connector then I would have to plug a molex output into the modular PSU and it all starts getting cluttered!

I can see the 3 pin headers with voltage control getting blown very easily, I would hope a 4 pin version would be much more resilient.

The correct way to do this would be a microcontroller (PIC probably) measuring the tacho of the master fan, and controlling a PWM signal to a slave fan to make it get the same speed. That would work with different fan sizes & makes, but I couldn't find such a beast.

Edit to add: Nice to see Scan do the 2 way split cable though, shall add one to the next order.

[Biscuit]

Do you have a spare SATA power output?

http://www.scan.co.uk/products/akasa...-black-braided

http://www.scan.co.uk/products/akasa...-black-braided

[DanceswithUnix]

Yes I do, and three fans is plenty, cheers!

[Pob255]

I use one, from phobia, it's actually got an additional 3pin header to supply additional power to the 2nd fan, however I don't need it so I cut it off so not to have a lose cable.

You need to check your motherboard manual it should list somewhere the max ampage on the fan header, if I remember correctly my M5A99x Evo can supply 1amp on the cpu fan header, which is plenty for a pair of most fans.
Most motherboards cpu fan headers are rated around 1amp, but not all, best to double check.

The rpm for the pwm control will only be read off one fan, but pwm control is based off fan speed % so two fans at two different max rpm will work but the faster fan will always run faster.
If you're setting them up on a cooler as push+pull then ideally you do want a pair of identical fans for balanced air flow, again not strictly necessary but better.

[mikeo01]

I used one called Akasa smart PWM with three 0.6A Thermalright TY fans and its fine. Don't know the wire gauge but each channel probably supports up to 1.0A. It's not braided but does the job fine.

Word of warning definitely use identical fans because I tried to mix fans before and it ended up making them all go full RPM.

Here it is http://www.amazon.co.uk/gp/aw/d/B001J2YRUC/ref=mp_s_a_1?qid=1365624483&sr=8-1&pi=SL75