One PWM fan header lots of fans

[Tiggsmagoo2]

So I am building a new PC but the MOBO only has one 4 pin PWM header, which is the CPU header. I am looking at connecting a lot of fans with a hub but if I connect the hub to my CPU header all my fans will be controlled off of the CPU temps. Is that weird or an issue. I have two 3pin fan headers but all my fans are 4 pin PWM fans. Im not sure what I should do moving forward... 

[powertoys]

It's not weird at all as long as the hub is externally powered (from your PSU, and not from the header). Usually these headers are rated for 1A max, so using those splitters for 4+ fans powered only by the header is a REALLY bad idea. A lot of stuff on the motherboard rely solely on that CPU header.

 

And I'm not completely sure about the 4-pin fan on a 3-pin connector, but if I'm not mistaken, you will be able to connect it but it's gonna run at 100% speed.

 

 

[OhioYJ]

1 hour ago, powertoys said:

And I'm not completely sure about the 4-pin fan on a 3-pin connector, but if I'm not mistaken, you will be able to connect it but it's gonna run at 100% speed.

A 3 pin connector would typically just use DC voltage to control the fan speed, rather than a PWM signal.

[powertoys]

18 minutes ago, OhioYJ said:

A 3 pin connector would typically just use DC voltage to control the fan speed, rather than a PWM signal.

You're correct, although some motherboards - especially older ones - lack this feature and just run them at 100% speed all the time

[thrasher_565]

2 hours ago, powertoys said:

You're correct, although some motherboards - especially older ones - lack this feature and just run them at 100% speed all the time

there were older 4pin non pwm header on older mb like 775 ish maybe 1150. but most mb have pwm.

Edited February 14 by thrasher_565

[powertoys]

9 minutes ago, thrasher_565 said:

there were older 4pin non pwm header on older mb like 775 ish maybe 1150. but most mb have pwm.

They do, but not all of them can recognize that you plugged a 3-pin fan into the 4-pin CPU header that was expecting a PWM. They also lack a BIOS setting to make the 4-pin header behave like a 3-pin header.

[thrasher_565]

2 minutes ago, powertoys said:

They do, but not all of them can recognize that you plugged a 3-pin fan into the 4-pin CPU header that was expecting a PWM. They also lack a BIOS setting to make the 4-pin header behave like a 3-pin header.

ya bios is bs and ive had bad luck with em... "oh just set a pwm setting they say..." i have a mb that wont save settings no matter what...

 

i think some 4pin pwm fans do different things when it dose not have pwm signal so... some wont run, some 100% some like 50%

[NorKris]

19 hours ago, thrasher_565 said:

i think some 4pin pwm fans do different things when it dose not have pwm signal so... some wont run, some 100% some like 50%

not how that works..

 

19 hours ago, powertoys said:

They do, but not all of them can recognize that you plugged a 3-pin fan into the 4-pin CPU header that was expecting a PWM. They also lack a BIOS setting to make the 4-pin header behave like a 3-pin header.

all boards have dc controll