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PWM Y spliter on CPU header

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Go to solution Solved by Shyxlol,

I am not sure how big the resistor is on a LNA but from pictures i am going to guess it is a 1/2 watt resistor so i wouldn't use it before the Y splitter, maybe after.

 

Caution: Never use one Low-Noise Adaptor to slow down multiple fans. Always use one adaptor per fan.

 

From noctua's website. Looks like I remembered it correctly.

 

So just don't use the LNA, makes no sense with pwm anyway as most of us have stated.

okey so i asked a similar question a few days ago and didn't get a answer i could realy comprehend, so im going to take another approach i think might be easier. Is it okay to use a pwm y spliter on the 4pin cpu fan header as i don't have enough fan headers in my motherboard. the fans i will be using noctua nff12 x2 and nfa14 x4 i want to split the 2 nff12's on my cpu cooler with LNA's to the included y adapter and run on the cpu header, that way i can use the define r4's fan controler for 3 and the other 4pin on the motherboard for the 4th. i just want to make sure im not going to be running into any voltage problems with 2 what i belive to be 12v fans on one header.

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You can power as many as 3 fans off a single header, IIRC.

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You can power as many as 3 fans off a single header, IIRC.

 

I'm actually powering 6 3-pin fans off one header after asking Asus' support.

"An ASUS motherboard can maximum provide totally 2~4 Amps on all-on board Fan power connectors which means it provide up to 24~48W total capability.

8Amp is a safety-shutdown limit."

Was the reply I got from them and then in German something along the lines of "I could power up to ten 4 Watt fans off one header without problems".

 

 

(note: if you really power 10 off one header that means you shouldn't plug in more into different headers I guess)

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so will it reduce fan speed if i use 2 fans on 1 header? should i not use the low noise adapter?

i know theses are very much noobie questions so i thank all that put up with them.

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so will it reduce fan speed if i use 2 fans on 1 header? should i not use the low noise adapter?

i know theses are very much noobie questions so i thank all that put up with them.

 

No, it won't. It just means that you control both fans simultaneously which shouldn't create any issues considering you're planning on using the same fan. Using the LNA is up to you I think, you're using pwm fans after all which should make it easy to speed them up/slow them down as you wish. Not using the LNA might make it look cleaner and give you the option for a higher max rpm.

 

And you also need to check the LNA description, not sure if you're even allowed using it in front of a Y splitter!!! Definitely check that.

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okey so one last question, arnt the headers only able to output 12v? how does it handle the x2? im sure it is safe im just not sure how it is possible to remain safe with the 12 volts.

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I am not sure how big the resistor is on a LNA but from pictures i am going to guess it is a 1/2 watt resistor so i wouldn't use it before the Y splitter, maybe after.

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okey so one last question, arnt the headers only able to output 12v? how does it handle the x2? im sure it is safe im just not sure how it is possible to remain safe with the 12 volts.

i lied one more on top of this one, i still didnt get a answer on this being okey to do on the cpu fan header, i know it is now safe to do on a regular 4 pin but im more curious about the cpu fan header

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okey so one last question, arnt the headers only able to output 12v? how does it handle the x2? im sure it is safe im just not sure how it is possible to remain safe with the 12 volts.

 

Having two fans doesn't increase the voltage, it just increases the amperage. 

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If it is a PWM fan to begin with there is no reason to use a LNA  in my opinion .

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i lied one more on top of this one, i still didnt get a answer on this being okey to do on the cpu fan header, i know it is now safe to do on a regular 4 pin but im more curious about the cpu fan header

 

Yes it's perfectly possible to run a Y-splitter on the CPU header and run 2 PWM fans. Even the highest capacity fans will run just fine. Just make sure to use two identical fans.

 

Low noise adapters aren't really needed on PWM fans, you wont notice the difference.

 

A fan splitter creates a parallel circuit, so they'll both receive the full 12v (http://en.wikipedia.org/wiki/Series_and_parallel_circuits)

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I am not sure how big the resistor is on a LNA but from pictures i am going to guess it is a 1/2 watt resistor so i wouldn't use it before the Y splitter, maybe after.

 

Caution: Never use one Low-Noise Adaptor to slow down multiple fans. Always use one adaptor per fan.

 

From noctua's website. Looks like I remembered it correctly.

 

So just don't use the LNA, makes no sense with pwm anyway as most of us have stated.

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Thanx to both Shyxlol and Syfes, and all others wish i could give you both the solve credit, not that it matters much lol.

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