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About LinkBacksHi everyone, if I've got three case fans (2 front intake, 1 rear exhaust) and only one system fan header on the motherboard, how can I connect up all of the fans so that they all operate at a lower speed (say, half speed)?
Hi everyone, if I've got three case fans (2 front intake, 1 rear exhaust) and only one system fan header on the motherboard, how can I connect up all of the fans so that they all operate at a lower speed (say, half speed)?
Assuming there are all 3-pin motherboard-connection fans, you have a few possibilities:
splitter cables
You'll need to check the max current draw for your motherboard fan headers, but it's possible that the header will provide enough current to run three fans (after all, fans are not particularly high power devices). Then you could simply buy some splitter cables for a couple of quid each.
dedicated fan controller
Probably the preferred option. I've just had a quick google and you can actually get high-current PCI slot fan controllers that will run multiple fans at one speed, or you could get a multi-channel controller so each fan can be adjusted individually. Expect to pay anywhere from a tenner upwards - for instance here's Scan's range: https://www.scan.co.uk/shop/computer...an-controllers
I got a 3-way splitter from scan which is powered off PSU (sata) but still takes the mobo signal from the header so you still get PWM but without overloading the mobo - cost £5. Akasa P something (Scan stuck their label over the model number - but their code is LN46345).
All three fans are 3-pin fans. If I connect a splitter cable (powered via SATA power) to them and provide input to the splitter from the motherboard SYS_FAN connector, would that work?
I think the Akasa splitter cable is part number CBFA07, which has five outputs.
If you just want them to run at a constant low speed, you could do the old 7v mod and power them straight from a molex
https://youtu.be/SyrvdDkS_SA
Originally Posted by ik9000
Those both look to be PWM splitters so I'm pretty sure they'd only work with PWM fans.
What motherboard is it? As I say, if you're careful with your choice of fans you might find the mobo header can provide enough current to run three fans anyway, just using passive splitter cables... otherwise I don't think you'll be able to use the motherboard's fan speed control, and will have to invest in some kind of powered fan controller...
I'd hook them up a fan controller to be honest.
Grab that. Get that. Check it out. Bring that here. Grab anything useful. Take anything good.
Any fan will run off a PWM cable - it just won't have the PWM speed adjustment and runs always at max if it's a 3 pin connector instead of 4. The point is it's a powered cable from the PSU so it won't overload the mobo. You could buy a 3 pin version but why bother? This way you have one you can use in the future for a PWM fan like your CPU cooler should you want to. My CPU has two fans on it and with only mobo header you can't avoid having to use a splitter for that.
No cost of a fan controller, no loss of a port to have to put it in, no ugly front panel. And £5. It's a no brainer for me. You only need a fan controller where you want to be able to adjust performance (or noise) on the fly and set each fan differently. Otherwise it is a waste of time and money.
I'm awaiting delivery of this splitter (Akasa AK-CBFA07-45 Flexa FP5S PWM Splitter Cable):
https://www.amazon.co.uk/dp/B008PO4X2E/
It's powered via a SATA power connector from the PSU. It's a PWM splitter and all my fans are 3-pin. I don't know whether I'll be able to control the fan speed through voltage with this arrangement but I'll wait and see. I know that all of the fans will work easily and there's no danger to the current drawn from the motherboard connector.
Two of the fans are 0.16A but I don't know that the third one is - it's the default 120mm that came with the Silverstone PS11B-Q - I'll remove it later to see if there's anything written on it. I think in theory I could have plugged all of them in to the SYS_FAN connector with a simple 3-way splitter cable as all three should be under 1A combined but didn't want to risk it.
If the fans all fly at full speed with the Asaka splitter then I'll just remove two of them and leave the one default intake fan that was supplied installed in the case and plug that directly into the SYS_FAN. I just had two fairly decent fans from another case that I wanted to use up.
You cant control the fan speed of 3pin (voltage controlled) fans with that adapter, it supplies 12v volts directly from the sata connector to each fan.
Yes, I know that, but since the OP specifically asked about running all three fans at a lower speed, the lack of speed control means it won't work for what they want to do. Perhaps I should have been explicit about that in my answer, but I was kind of assuming people would infer that bit from the question.
As the OP wants to control the speed of the fans (even if that currently just means running them all at a single lower speed), a fan controller is the best option, and given you can get a 3 channel controller for < £15 it's not an exorbitant expense, and would then give them the option of individually controlling the speed of the fans later if they found that suited their purposes better.
And, you know, it's a better option than spending a fiver on something that won't actually do the job they want...
I dont understand why a 5v/7v adaptor mod is an issue TBH :/
Its easy and I'm guessing everyone has a fair few of these kicking about in a drawer/box somewhere as they come supplied with fans so the cost is.. er... zero
https://www.techpowerup.com/articles/other/137
It isn't, if it worksI knacked a fan once because it wouldn't start at 7v and burned out before I realised...
The only key then is getting sufficient adapters. I'm pretty sure I don't have more than 1 molex-fan adapter at home (and I might not even have that many). And if you have to go out and buy the adapters to do the mod, you may as well buy a fan controller.
That much I agree with for sure.It isn't, if it works
The only key then is getting sufficient adapters. I'm pretty sure I don't have more than 1 molex-fan adapter at home (and I might not even have that many). And if you have to go out and buy the adapters to do the mod, you may as well buy a fan controller.
I guess its just me with a tonne of them. Im pretty sure I chucked a load out earlier this year because the little draw in my organiser was full!
Yeah, I seem to end up with many Molex - SATA power adapters, and passive DVI - VGA adapters. Not a right lot of fan bits and pieces - although I did bulk buy some NorthQ CPU coolers when they were about a fiver on Scan a few years back, and they all came with little 3-pin inline fan controllers, so I've got several of those lying around still (although last time I tried to use one it was with an LED fan and it made the most horrendous whine I've ever heard from a PC!).
Actually, those coolers were phenomenal value - they were multi-socket and also suitable for GPUs, and came with fan controllers AND a set of little stick on heatsinks for GPU RAM...
https://www.amazon.co.uk/Evercool-EC...4192553&sr=8-1
(I just noticed 2 of the outputs are 5V...)
or
https://www.amazon.co.uk/KabelDirekt...y+fan+splitter
and
https://www.amazon.co.uk/TOOGOO-Nois...4192475&sr=1-1
if you don't have adapters kicking about
This is an interesting controller:
https://www.amazon.co.uk/Cooling-con...y+fan+splitter
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