3pin fan header on mobo for 4 pin controller

[Marie Rose]

Hello does this ARCTIC Case Fan Hub, 10 port. Work on this mobo? If I plug it into the 3 pin fan on mobo and connect it to sata, then all the fans I got to the hub. (all fans are ARCTIC P12 PWM 4 pins.)

 

https://www.arctic.de/en/Case-Fan-Hub/ACFAN00175A

[VIVO-US]

The 3-pin header doesn't support PWM, so the fans will likely run only at full speed if connected to that.  If you use the CPU fan header, then that will give you PWM control and you can plug the CPU fan into the hub along with the case fans.

[Agall]

15 minutes ago, Marie Rose said:

Hello does this ARCTIC Case Fan Hub, 10 port. Work on this mobo? If I plug it into the 3 pin fan on mobo and connect it to sata, then all the fans I got. (

all fans are 4 pins so pwm.)

 

https://www.arctic.de/en/Case-Fan-Hub/ACFAN00175A

You can generally mix-match between 3 pin and 4 pin. Its whether or not DC speed control is worth it or not if you're using a 3 pin header as a fan control for a hub.

 

You can always modulate fan speed with the DC voltage, but can only control a PWM fan with PWM from a proper 4 pin header. 

 

That hub will either always pump out full speed going from a 3 pin header or allow DC speed control. Hard to say without actually testing it. The rationale being it might ignore the 3 pin's DC voltage modulation in favor of a full 12V from the SATA power, but I don't see it listed as PWM or DC control.

[Marie Rose]

4 minutes ago, Agall said:

You can generally mix-match between 3 pin and 4 pin. Its whether or not DC speed control is worth it or not if you're using a 3 pin header as a fan control for a hub.

 

You can always modulate fan speed with the DC voltage, but can only control a PWM fan with PWM from a proper 4 pin header. 

 

That hub will either always pump out full speed going from a 3 pin header or allow DC speed control. Hard to say without actually testing it. The rationale being it might ignore the 3 pin's DC voltage modulation in favor of a full 12V from the SATA power, but I don't see it listed as PWM or DC control.

So what's the smartest thing to do here?  

[Agall]

1 minute ago, Marie Rose said:

So what's the smartest thing to do here?  

As @VIVO-US pointed out, you can always use the CPU fan header to get PWM. So you could potentially ignore that 3 pin header all together.

 

The motherboard will generally verify in POST that a fan is hooked up to the CPU_FAN header, but I doubt a hub will give issues with this (though it is possible). 

 

I'm assuming at least one of these parts you already own. Otherwise, you could just get a USB controlled fan hub like a Corsair Commander.

[Marie Rose]

2 minutes ago, Agall said:

As @VIVO-US pointed out, you can always use the CPU fan header to get PWM. So you could potentially ignore that 3 pin header all together.

 

The motherboard will generally verify in POST that a fan is hooked up to the CPU_FAN header, but I doubt a hub will give issues with this (though it is possible). 

 

I'm assuming at least one of these parts you already own. Otherwise, you could just get a USB controlled fan hub like a Corsair Commander.

I own the hub already and the cpu, mobo and ram. Can I mount the CPU cooler into the fan hub as well if i plug the fan hub to the top 4 Pin cpu header on mobo?

[Marie Rose]

14 minutes ago, VIVO-US said:

The 3-pin header doesn't support PWM, so the fans will likely run only at full speed if connected to that.  If you use the CPU fan header, then that will give you PWM control and you can plug the CPU fan into the hub along with the case fans.

Oh damn, I missed this reply, thanks for clarifying! 

[Agall]

15 minutes ago, Marie Rose said:

I own the hub already and the cpu, mobo and ram. Can I mount the CPU cooler into the fan hub as well if i plug the fan hub to the top 4 Pin cpu header on mobo?

That's what I would do, otherwise its likely that hub doesn't support DC fan control.

 

You can honestly try either setup if you already own the hardware, I just suspect that the hub won't care for DC control so the fans might run at 100%.

 

Fans are 12Vdc.

 

The tach signal is so the board can tell what speed the fans operating at, really here, the 12v and GND are the important ones.

 

A 3 pin fan controls speed by lowering the 12V, so there's less torque to the fan's motor, though this simply doesn't work when you get to a low enough voltage (no longer has enough excitation to move at all).

 

A 4 pin fan controls speed by always receiving 12V, then modulating that 12V with PWM signals. It'll effectively interrupt the voltage at a specific period, effectively giving the fan little or big pushes.

 

 

If your hub doesn't support DC voltage control like how a 3 pin works, then the fans will likely just be stuck at 100%. You could use the in-line resistors (low speed adapter) to lower the speed this way, but you'd need that for every fan since its likely that hub supplies 12Vdc to those fans from the SATA power connector.

 

So really, either are fine depending on the use. The hub might not even require a header at all if it can simply power the fans via the 12V rail from the SATA power and you don't care that they're running at 100%. If you want proper speed control of the hub, you'll likely have to use the CPU_FAN header instead.

[OhYou_]

27 minutes ago, Marie Rose said:

So what's the smartest thing to do here?  

what the manual says basically

 

Connect the hub to cpu fan header, and connect the cpu fan up to port 1.

[Marie Rose]

3 minutes ago, OhYou_ said:

what the manual says basically

 

Connect the hub to cpu fan header, and connect the cpu fan up to port 1.

Thank you everybody, this forum is great.