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PWM Hub question

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Skynight

Registered
Joined
Oct 31, 2008
Hello,

I recently bought a Noctis 450 which comes with an integrated 8-port fan hub for PWM.

I'm currently looking for case fans, preferably with LED. I noticed that 4-pin are usually PWM and 3-pin are "static"...
How does this work ? The fan hub only accepts 3-pins...should I care if the fans are "static" and not 4-pins?

Sorry, don't know how to clearly describe my question.

For instance,

http://www.newegg.com/Product/Product.aspx?Item=N82E16835106327
http://www.newegg.com/Product/Product.aspx?Item=N82E16835553013

Would that benefit from PWM ?

Thanks in advance.
 

ATMINSIDE

Sim Racing Aficionado Co-Owner
Joined
Jun 28, 2012
You'll benefit from PWM if you're trying to speed control your fans.

If you get a PWM splitter and connect it to a PWM fan header on the motherboard it is a great way to keep your system quiet at low loads.
 

NiHaoMike

dBa Member
Joined
Mar 1, 2013
That case has a buck converter so it is only designed to work with 3 wire fans. If you want to use PWM, you'll have to make or buy a splitter and ignore the built in "splitter".
 

Conumdrum

Member
Joined
Sep 15, 2007
Location
Small town Emlenton, PA
So, the case input (adaptor) is a PWM connector (4 pin) from the Mobo, usually CPU temp. The splitter has PWM 4 pin input AND AND a molex connector? And outputs only 3 pin. Meaning the mobo will send PWM speed outputs to the adaptor and convert the PWM mobo signal to analog speed signals for the 3 pin outputs?

Is that what you mean?
 

NiHaoMike

dBa Member
Joined
Mar 1, 2013
That's how it works. It's basically a very simple "digital amplifier".

BTW, it's surprisingly easy to DIY one.
 

inVain

Member
Joined
Apr 4, 2011
Hello,

I recently bought a Noctis 450 which comes with an integrated 8-port fan hub for PWM.

I'm currently looking for case fans, preferably with LED. I noticed that 4-pin are usually PWM and 3-pin are "static"...
How does this work ? The fan hub only accepts 3-pins...should I care if the fans are "static" and not 4-pins?

Sorry, don't know how to clearly describe my question.

For instance,

http://www.newegg.com/Product/Product.aspx?Item=N82E16835106327
http://www.newegg.com/Product/Product.aspx?Item=N82E16835553013

Would that benefit from PWM ?

Thanks in advance.


if the hub were able to control 3p fans, it'll work with anything.
just be careful as they are typically load sensitive (too heavy load might kill the hub)
 

ATMINSIDE

Sim Racing Aficionado Co-Owner
Joined
Jun 28, 2012
if the hub were able to control 3p fans, it'll work with anything.
just be careful as they are typically load sensitive (too heavy load might kill the hub)

The big benefit of PWM is the wider control range that it gives over voltage control.
 

inVain

Member
Joined
Apr 4, 2011
The big benefit of PWM is the wider control range that it gives over voltage control.

agreed.
PWM is newer and better when it come to "control" feature.

to me the OP seems that he wanted to use his hub which only have 3p output.
as mentioned by Conumdrum I think that hub had DAC on it.

so if that the case, that hub will convert the PWM to voltage.
increase the hub compatibility with fans, but wasting the PWM feature on a PWM fan.
 

JrClocker

AKA: JrMiyagi
Joined
Sep 25, 2015
I have the same case.

The PWM hub is rated for 30 W.

The input into the hub is a 4 wire connector, but the fan control outputs are 3 wire.

I have connected both 4 wire and 3 wire fans to the hub. You can do either, but not both. (i.e. if you connect a 4 wire and a 3 wire fan to the hub it won't run correctly). You can control the fan speed of all connected fans via the PWM control on your motherboard.