Overloading CPU fan header/compatability

WolfyUK · 2 Jul 2020 at 22:53

I'm sitting on a 5 pack of Arctic P12 PWM/PSTs, and I'm planning on buying something in a Ryzen (not 100% sure which just yet). Arctic suggest that 5 fans running from the CPU header is fine - I'm thinking of running 4 of the P12s and the Wraith together.

Does anyone know if
a) this will overload the header or
b) the PWM/PST (which is 4 pin header but the piggyback is 3 cables) will interfere with the mb's ability to control the Wraith?

Ta.

Minibiker · 3 Jul 2020 at 00:00

What motherboard do you have? It should have atleast one Cha_Fan header on! That's where I'd start plugging fans, not on the same header as a CPU cooler

WolfyUK · 3 Jul 2020 at 01:19

Currently a venerable Gigabyte Z68 which only has a 4 pin header for the CPU fan - Arctic (surprisingly, to me at least) seem to recommend chaining the case fans in with the CPU cooler in that case.

In a few weeks it will be... probably an X570 Tomahawk, so this won't be an issue.

(edit for clarity - the chassis fan headers are 3 pin)

PieEater · 3 Jul 2020 at 08:42

4 Pin fans will work on 3 pin headers the only difference being fan speed will be controlled via DC (voltage control) rather than PWM so as Minibiker suggests it would be better to use the headers on the board rather than having all of the fans on the CPU fan header.

Arctic reccomend not having more than 5 fans on the same header but to check your motherboards sepcifications for the header as it will need to be rated for more than 1 Amp to be able to do this (each P12 fan can draw 0.24A at 100%). However just because you can do something doesn't always make it a good idea to do it, and personally I wouldn't risk blowing the one critical fan header on the board by doing this.

Great fans BTW :cool:

WolfyUK · 3 Jul 2020 at 17:04

Wise words, I think. Won't matter when I get the new board as it will have more pwm headers, but for now I'll do what you suggest.

PieEater said:
Great fans BTW

Yeah man, I got a bit covid-taxed since stock is so low, but they seem worth every penny.

Mcnumpty2323 · 3 Jul 2020 at 17:10

Personally 3 fans off 1 header
Unless it's a high amp 2A+ header
The fans may draw more power starting up than once running so I wouldn't personally run 5 off 1 header

EsaT · 3 Jul 2020 at 20:34

Arctic P12 PWMs have ludicrously skimpy current draw.
80mA per fan, so five fans per connector is safe in any motherboard.

Grimley · 4 Jul 2020 at 20:36

If you are worried about overloading the fan header buy one of these. It powers the fans with the sata connector & just uses the fan header for PWM. I have one in my encoding rig.

My basket at Overclockers UK:

1 x Akasa FLEXA FP5S 5 Fan PWM Controller (AK-CBFA07-45)= £4.99

Total: £7.73 (includes shipping: £2.74)