4 Pin fan, can I just run it off the mobo

Lisapete · 25 Aug 2017 at 11:15

Silly question

Looking to get 6 of these https://www.overclockers.co.uk/akas...mance-pwm-air-ripper-blade-fan-fg-073-ak.html

Wanting them to run 100% all the time, can i just plug them in this and use the 4 pin molex only?

https://www.overclockers.co.uk/akasa-ak-cb002-pwm-fan-splitter-cable-cb-031-ak.html

ttaskmaster · 25 Aug 2017 at 12:06

Off the Molex, yeah sure. Just use enough splitters and you're good.

Off the Mobo... Possibly not. Sometimes those headers can only deliver enough oomph for one or two fans, especially on older boards. There are ways around it with threads explaining, but they're fiddly and not my specialty.

doyll · 25 Aug 2017 at 23:47

Why buy PWM fan and a PWM splitter that uses PSU for power and PWM signal from motherboard fan header and then run fans at full speed all the time. Only time case fans need to run full speed is when CPU and GPU coolers are running full speed.

Lisapete · 29 Aug 2017 at 09:19

doyll said:
Why buy PWM fan and a PWM splitter that uses PSU for power and PWM signal from motherboard fan header and then run fans at full speed all the time. Only time case fans need to run full speed is when CPU and GPU coolers are running full speed.

It's for a GPU miner

The fan that meet the specs only come in PWM

Expand your horizons perhaps.

doyll · 29 Aug 2017 at 13:03

Lisapete said:
It's for a GPU miner

The fan that meet the specs only come in PWM

Expand your horizons perhaps.

Sorry but that did not answer the question .. which was 'Why not use PWM control so fans only spin as fast as needed based on GPU temp which is dependent somewhat on room ambient air temp?'

james_2k · 1 Sep 2017 at 13:09

If you dont want fan control then just plugging them into the molex will spin them at 100%, if you want to control them, i use this: https://www.overclockers.co.uk/akas...-5-pwm-case-fans.-ak-cbfa03-45-cb-070-ak.html

works well and you can plug the extra fan into another slot on the mainboard.

doyll · 1 Sep 2017 at 13:19

I have used thos Akasa PWM splitters with PSU power, but they are poorly designed and built. The first image shows the proble of too many wires terminating into a single fixed pin where the flex until wire become brittle and break off of connector.

The EK Waterblocks model is much better.
https://www.overclockers.co.uk/ek-water-blocks-ek-cable-splitter-4-fan-pwm-extended-wc-9cq-ek.html

Tealc · 1 Sep 2017 at 17:15

For 100% speed all the time something like...

https://www.overclockers.co.uk/akas...4-pin-molex-to-4-fans-ak-cb001-cb-030-ak.html

..would be more appropriate, perhaps with the side removed to accomodate 4 pin fans, or a 4 pin compatible variant. Or one of the PCB distribution board types.

Or buy 3 pin fans as the additional cost for PWM fans that affords the digitial control method is totally wasted if you are just going to run them at 100%.

Not sure why you are committed to these particular fans as any fan running at 1900rpm or so will produce, more or less the same level of airflow, static pressure and howling noise levels given you choose a 7 bladed fan.

james_2k · 1 Sep 2017 at 17:28

doyll said:
I have used thos Akasa PWM splitters with PSU power, but they are poorly designed and built. The first image shows the proble of too many wires terminating into a single fixed pin where the flex until wire become brittle and break off of connector.

The EK Waterblocks model is much better.
https://www.overclockers.co.uk/ek-water-blocks-ek-cable-splitter-4-fan-pwm-extended-wc-9cq-ek.html

working fine for me

doyll · 2 Sep 2017 at 11:56

james_2k said:
working fine for me

It's only a matter of time. Post up after you do a half dozen times of re-arranging components and cables .. as in when one fan starts running full speed when the others are at idle.

Tealc · 2 Sep 2017 at 13:49

Agree with doyll. Stuffing two wires into a terminal designed for one is bad enough but stuffing an extra one in there is not a good idea.

I've lost count of the number of people who bought one of the Akasa and then complained that they didn't work, only later to find that the wire had broken off inside the terminal.

I even bought one before realising how they'd done it, saw how bad it was and never used it.

james_2k · 2 Sep 2017 at 15:51

doyll said:
It's only a matter of time. Post up after you do a half dozen times of re-arranging components and cables .. as in when one fan starts running full speed when the others are at idle.

then ill buy another one, they cheap mang!

doyll · 3 Sep 2017 at 13:07

james_2k said:
then ill buy another one, they cheap mang!

Are you really that bull headed that you won't listen to Tealc's many years of experience and logic (or mine) and when your Akasa splitter fails you will not pay 2 quid more for one that will not fail you later on?
If you had known what we are saying our posts the first time you bought and had paid the extra 2 quid it would be cheaper than buying 2 Akasas' that stress fatigue and break.

james_2k · 3 Sep 2017 at 14:06

Erm. Yes?

It's a fan splitter. I couldn't care less. It's working fine. If that stops being the case at some point I'll change it. :cool:

doyll · 3 Sep 2017 at 14:29

As P. T. Barnum said, there's one born every minute.

james_2k · 3 Sep 2017 at 14:32

And his fans work perfectly

doyll · 3 Sep 2017 at 14:45

Lots of sucker fans.