# Do you use case fans plugged into Mobo or direct power?



## AntDeek (Feb 3, 2017)

New build today. Wondering if I should have the case fans always at max, or allow my ASUS board to handle all that?


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## fullinfusion (Feb 3, 2017)

I use a 5 channel fan controller, so none of the above.


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## phanbuey (Feb 3, 2017)

it depends on your fans... I wouldn't hook up 2k RPM deltas to your mobo, but if you have a silent setup with low rpm fans then you can safely daisy chain a few of them off a mobo header and control them from the BIOS


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## therealmeep (Feb 3, 2017)

I usually let the mobo decide mine because I don't have much interest in the fine tuning of my case fans, for something like CPU fans though i use a control program in Windows that lets me control them from the mobo header.


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## Sasqui (Feb 3, 2017)

In all the builds I've done, using MB fan headers and BIOS speed control has worked great.  PC heats up, fans spin faster and cool them back down again.  Fans stay clean for longer too.  I wouldn't go any other way.  My 360 radiator has three fans connected to speed controllers, that's the only exception.


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## eidairaman1 (Feb 3, 2017)

I have 4 fans on 2 controllers built into my case. The cpu fans are controlled by the motherboard.

I personally prefer manual control over my fans with my fingers vs letting software control the case fans, It helps keep the noise down. Plus I've had my fans at lowest setting for Ryzen Blender and the system did fine with them. The cpu fans reved where needed.


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## AntDeek (Feb 3, 2017)

Cool. The fans in question are 120mm from my NZXT S340 chassis. It came from the factory with a molex connector but I'm thinking about plugging them into the main board


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## rtwjunkie (Feb 3, 2017)

I do both.  I see that option missing.


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## dorsetknob (Feb 3, 2017)

rtwjunkie said:


> I do both. I see that option missing.


Also do both and always will for future builds   its the Best of Both worlds and gives better control for Air flow


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## Sasqui (Feb 3, 2017)

AntDeek said:


> Cool. The fans in question are 120mm from my NZXT S340 chassis. It came from the factory with a molex connector but I'm thinking about plugging them into the main board



Nice case, but I hate when they do that!  How many wires from the fans to the molex connectors?


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## DRDNA (Feb 3, 2017)

Both But not if they have a Molex. Molex goes to PSU only for me.


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## TheoneandonlyMrK (Feb 3, 2017)

AntDeek said:


> Cool. The fans in question are 120mm from my NZXT S340 chassis. It came from the factory with a molex connector but I'm thinking about plugging them into the main board


It won't have a rpm sensor wire and it will have a molex connection I'm guessing so it won't plug directly into your motherboard , your best of connecting to psu.
It's sometimes possible to add the sensor wire as it's normally just the wire missing, I've done this before by cutting off a 3 pin wire from a duff fan and soldering it on ,not really worth it tbh.
Case fans are made to be relatively inoffensive from a noise pov.


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## jboydgolfer (Feb 3, 2017)

I can't think of a good reason to direct connect the fan to a power supply unless it's got a speed controller built into the power plug.

 The way I look at it there's only two reasons to do it that way. One being that you had no other choice. Two , your PC is running so hot that the fans need to be on 100% all the time. Either way the system needs to be reconfigured if either of those are true.


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## TheoneandonlyMrK (Feb 3, 2017)

jboydgolfer said:


> I can't think of a good reason to direct connect the fan to a power supply unless it's got a speed controller built into the power plug.
> 
> The way I look at it there's only two reasons to do it that way. One being that you had no other choice. Two , your PC is running so hot that the fans need to be on 100% all the time. Either way the system needs to be reconfigured if either of those are true.


While I don't disagree totally,
The fans have molex connectors, they won't plug into a fan controller or mobo and neither would know what speed it's running at , the faccts ain't pretty but they are true.
So like I said get your soldering iron out , or splice it onto another 3 pin fans wire or
Just plug it into the PSU as it was designed to be.


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## rtwjunkie (Feb 3, 2017)

jboydgolfer said:


> I can't think of a good reason to direct connect the fan to a power supply unless it's got a speed controller built into the power plug.
> 
> The way I look at it there's only two reasons to do it that way. One being that you had no other choice. Two , your PC is running so hot that the fans need to be on 100% all the time. Either way the system needs to be reconfigured if either of those are true.


High RPM fans that you want to produce a constant flow of air. Less strain on the motherboard than overloading all the fan locations with a lot of electricity through small traces.


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## eidairaman1 (Feb 3, 2017)

I use my case controolee which connect to 2 molex connectors on the psu, its a run of the mill potentiometer/rheostat, noyhing special but it does what I need it for.


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## Flow (Feb 3, 2017)

Yeah, I also use both. Though I prefer the mobo fan headers because of rpm monitoring.
As for full speed or auto etc, that depends on users preference.
For instance, not auto for motherboard header, it takes too long for it to kick in. For cpu manual. Since intel chips jump over 50°C in an instant if you fire up a game, I've set it to go 100% from 50 and up.
So with simple webbrowsing or watching a movie it stays just below that and produces no sound at all at approx. 600 rpm per cpu fan. I did have to lower the warning for low cpu rpm setting though.
I have one front case fan at 900 rpm, the other front case fan is 1500 but makes too much noise for my taste so I limited it to around 1200 rpm. Strangely though the rear fan is the same 1500rpm and barely audible at that speed. The sidepanel fan is 1200 rpm silent type so full speed. My top fan doesn't seem to do better at full speed or lower. But I've set the switch to full speed. It's an Antec sixhundred case.

Experimenting with various fans can be interesting, some low rpm fans can work better than other higher rpm fans for instance. Noise is also a factor after all.


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## jboydgolfer (Feb 3, 2017)

Where does OP live?
 I must have my bodyweight in case fans that have three and four pin connectors



rtwjunkie said:


> High RPM fans that you want to produce a constant flow of air. Less strain on the motherboard than overloading all the fan locations with a lot of electricity through small traces.



 Every PC I've ever built I install anywhere from 3 to 7 case fans including the CPU cooler and I've never overloaded any motherboard in my career of the building and repairing PCs. Not saying it couldn't happen, but maybe you have?ill have to take your word on that


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## Arctucas (Feb 3, 2017)

Yes.


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## CAPSLOCKSTUCK (Feb 3, 2017)

i voted "other" as i dont have any case fans installed. I have 2 fans on my rad and one small fan on the northbridge. Thats all the fans i need 

its 26 C in my sitting room this evening and after 2 hours of gta my PC looks like this.


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## DeathtoGnomes (Feb 3, 2017)

"other". My control is from a hub which is a hybrid of both mb and direct.


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## TheoneandonlyMrK (Feb 3, 2017)

I think I'm at 16 fans in case now all mobo headers full, one drives 3 fans .
plus a four head fan controller with 3x3 and a single on one , burning the controller out on quality kits hard.
@ Caps your being speculous with your info  how many rads/aio


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## HammerON (Feb 3, 2017)

Fan controllers. None are plugged into motherboard.


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## AntDeek (Feb 3, 2017)

Sasqui said:


> Nice case, but I hate when they do that!  How many wires from the fans to the molex connectors?



Two way splitter


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## IBRAHIM_007 (Feb 4, 2017)

* motherboard

for low rpm fans like 200mm 700 RPM not big deal , you can connect it directly to power supply or motherboard ( if it have lot of headers ) and set it to max speed if you want

but for high or mid rpm fans , you definitely need to connect it to motherboard ( to control and measure RPM , and make profiles for fans )

fan noise is not just about the RPM , its also about the type of bearing and lot of stuff

i recommend fan controller ( if your motherboard have just few headers and you have lot of fans )
because connecting lot of fans to single header using splitter will put stress on the motherboard header

even though i remember there is adapter or splitter that take power from power supply while allowing the motherboard to control the fan .. im not sure of this .. i think its mod for 4 pin PWM fans .. not 3 pin fans ( most case fans )

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read this before buying fan controller , because some of them have lot of disadvantages

i took screen shot because its long
https://s29.postimg.org/fxh1yvqbr/fan_controller.jpg

the only good thing about some fan controllers is that they can handle lot of fans + high wattage fans


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