[SOLVED] Can I get away with 1 exhaust fan connected to the PSU and 2 connected to the motherboard?

[momowicket]

I've bought a PC and all the parts are coming in and I realised that the Asus Prime b450m-k only has one chassis 4 pin slot and one cpu 4 pin slot. I bought one splitter and a fan extender cable just in case but I now realise I need 2 splitters. I intend to connect exhuast to the PSU and both front intakes to the motherboard. Anyway could this be bad for the PC?

Thanks in advance,

 

[RememberThe5th]

You can use the fan splitter up to 1A~, depending how much does your fan use , for example your fan uses 0.2A you can hook up to 4 fans via one hub.

And yes you can, but I dont know will it be loud for you since it will run at max (unless you hook it up to 5V).

 

[momowicket]

You can use the fan splitter up to 1A~, depending how much does your fan use , for example your fan uses 0.2A you can hook up to 4 fans via one hub.

And yes you can, but I dont know will it be loud for you since it will run at max (unless you hook it up to 5V).

Whats '1A~'? And what does 'unless you hook it up to 5 volts' mean?
Also do you know any on the cheap side fan hubs that are reliable?

 

[RememberThe5th]

1A is the unit of amperage aka current.
For instance lets say Voltage is how fast the river is going, amperage is how wide the river is.

The issue is if you hook up the fan to the PSU, the fan is rated at 12V which runs it at max RPM (Similar to reving the car's RPM).
You can connect it, it wont do any damage but the fan might be noisy (Depending which type of fan you have, there are low rpm one's high rpm, etc.)

Yes there are fan hubs , just by searching on ebay/amazon it will give you search results.

 

[momowicket]

1A is the unit of amperage aka current.
For instance lets say Voltage is how fast the river is going, amperage is how wide the river is.

The issue is if you hook up the fan to the PSU, the fan is rated at 12V which runs it at max RPM (Similar to reving the car's RPM).
You can connect it, it wont do any damage but the fan might be noisy (Depending which type of fan you have, there are low rpm one's high rpm, etc.)

Yes there are fan hubs , just by searching on ebay/amazon it will give you search results.

Thanks man, I'll probably either leave it connected the the PSU, buy another splitter or buy a fan hub.
This is the fan -https://www.pccasegear.com/products/40936
It runs at 1200rpm max which I think is considered normal and most people like to clock them down 500+.

 

[Paperdoc]

You can connect one case fan directly to a PSU output but then it will always run full speed and generate more noise than if you put it under mobo automatic control. So do it this way instead.

You have one Splitter. Don't bother with that one, just get this one as your second one (and only one you use)

https://www.newegg.com/Product/Prod..._re=coboc_fan_splitter-_-12-423-163-_-Product

It has THREE outputs from a single mobo fan header. To help understand some of the info above, any fan header can supply up to 1.0 A total current to all the fans connected to it using a Splitter. Your fans are spec'd at 0.16A current max each, so just under 0.5 A max for three. No problem using the Splitter and one mobo header. This will put all of those fans under automatic control based on a temperature sensor built into the mobo, so they will only run as fast as the need to to keep your case temps in proper control.

Those fans are of the 3-pin design. Although the mobo fan header and that Splitter are for 4-pin system, this will all work with those fans IF you make this small adjustment. After you get this all set up look in your mobo manual on p. 2-1 for how to enter the BIOS Setup system. It says to start up the system and press the "Del" key to Enter Setup. I find that, right after you push the power button as the machine starts to power up, you should HOLD that "Del" key down until the Setup opening screen appears (see p. 2-2). That way it won't miss the keypress. Once you get there, click on the QFAN Control item at bottom middle. It will show you things you can adjust separately for the CPU fan and CHA_FAN headers. Choose the CHA_FAN header. One option you can set is whether it uses PWM Mode or DC Mode to do its control work. Set that to DC Mode (required for your 3-pin fans), then use the F10 key to get to the Exit menu. There choose to Save Changes and Reset so your new setting is saved.

A couple notes for you - not problems, just things for you to know. Those fans are LED fans, and the blue LED lights in the frames are just connected in parallel with the motor. So, when your system is cold and needs little air flow for cooling, the voltage fed to the fans MAY make the lights go dim, and brighten up when the fans speed up. Not a problem. Another small point. The CHA_FAN header can read the speed of only ONE fan, so that Splitter will only send it one fan's speed signal to measure. There is a place in BIOS Setup and in other tools where you can see that if you want to. But the speeds of the other two fans on that Splitter / CHA_FAN header setup will be ignored completely and never displayed anywhere. Again, not a problem. Just make it a habit from time to time to check that they all still are working.

 

[Skpstr]

Thanks man, I'll probably either leave it connected the the PSU, buy another splitter or buy a fan hub.
This is the fan -https://www.pccasegear.com/products/40936
It runs at 1200rpm max which I think is considered normal and most people like to clock them down 500+.

Another alternative might be to look at a quieter fan. I added a 9-blade fan to the side of my last build, and because my cables were extremely messy (case had zero management room) and obscured the mobo, I just plugged it into the first PSU plug that was on top of the spaghetti pile. I didn't notice any noise increase.

 

[momowicket]

You can connect one case fan directly to a PSU output but then it will always run full speed and generate more noise than if you put it under mobo automatic control. So do it this way instead.

You have one Splitter. Don't bother with that one, just get this one as your second one (and only one you use)

https://www.newegg.com/Product/Product.aspx?Item=N82E16812423163&Description=coboc fan splitter&cm_re=coboc_fan_splitter--12-423-163--Product

It has THREE outputs from a single mobo fan header. To help understand some of the info above, any fan header can supply up to 1.0 A total current to all the fans connected to it using a Splitter. Your fans are spec'd at 0.16A current max each, so just under 0.5 A max for three. No problem using the Splitter and one mobo header. This will put all of those fans under automatic control based on a temperature sensor built into the mobo, so they will only run as fast as the need to to keep your case temps in proper control.

Those fans are of the 3-pin design. Although the mobo fan header and that Splitter are for 4-pin system, this will all work with those fans IF you make this small adjustment. After you get this all set up look in your mobo manual on p. 2-1 for how to enter the BIOS Setup system. It says to start up the system and press the "Del" key to Enter Setup. I find that, right after you push the power button as the machine starts to power up, you should HOLD that "Del" key down until the Setup opening screen appears (see p. 2-2). That way it won't miss the keypress. Once you get there, click on the QFAN Control item at bottom middle. It will show you things you can adjust separately for the CPU fan and CHA_FAN headers. Choose the CHA_FAN header. One option you can set is whether it uses PWM Mode or DC Mode to do its control work. Set that to DC Mode (required for your 3-pin fans), then use the F10 key to get to the Exit menu. There choose to Save Changes and Reset so your new setting is saved.

A couple notes for you - not problems, just things for you to know. Those fans are LED fans, and the blue LED lights in the frames are just connected in parallel with the motor. So, when your system is cold and needs little air flow for cooling, the voltage fed to the fans MAY make the lights go dim, and brighten up when the fans speed up. Not a problem. Another small point. The CHA_FAN header can read the speed of only ONE fan, so that Splitter will only send it one fan's speed signal to measure. There is a place in BIOS Setup and in other tools where you can see that if you want to. But the speeds of the other two fans on that Splitter / CHA_FAN header setup will be ignored completely and never displayed anywhere. Again, not a problem. Just make it a habit from time to time to check that they all still are working.

My plan until I but the splitter is to plug one into the power supply then leave the other two on the splitter. As you said in the bios I will the select CHA-FANS and set it to DC-mode over PWM-mode.

Also that splitter is on Newegg and being in Australia shipping prices is crazy(22AUD), and if I connect 2 splitters together you get a 3 way. I'll probably get this one with free shipping (https://www.amazon.com.au/gp/product/B0764CFVPV/ref=ox_sc_act_title_1?smid=A4SIMBWHQBJQ4&psc=1 )so I don't have 1 extra splitter sitting around (I've already ordered everything)

Thanks.

 

[Paperdoc]

You are right, of course. I did not mean you need exactly that 3-ouput Splitter. I meant only if you are buying an additional Splitter anyway, getting a three-output unit rather than a 2-output can be a simple solution at almost the same cost. But if you can't get that, "stacking" two two-output ones does the same job. Just FYI, of you get three 2-output Splitters and fit two into the outputs of the third, that stack gets you four outputs from one header.

 

[Paperdoc]

Thanks for Best Answer.