How do Y-splitters work with PWM connectors on Motherboards?

[amsga]

Hi All,

 

I am attempting to move from my current NZXT H710i to a new O11 Dynamic XL by the end of the year.

I notice that the O11 does not have any fans included and I am planning to get 3 Noctua NF-A12x25 as a side intake.

The problem I am facing now is that I am not sure if I can connect the Y-Splitters to the PWM connectors on my ASUS ROG Strix X570-F motherboad or not.

Likewise, is there a optimal configuration if I can do so?

I was thinking along the lines of two Y-Splitters, the first one connect to the motherboard and 1 fan, with the second connection connecting to the second Y-Spliiter and the remaining 2 fans.

 

Thanks for the help!

[IkeaGnome]

They work by getting the PWM signal from the first fan that uses all 4 pins. After that it just assumes they're all the same speed and sends the same pwm speed to all the fans.

 

The only thing to be aware of with them is to not go over the amperage rating of that header on the motherboard

[thrasher_565]

51 minutes ago, IkeaGnome said:

They work by getting the PWM signal from the first fan that uses all 4 pins. After that it just assumes they're all the same speed and sends the same pwm speed to all the fans.

 

The only thing to be aware of with them is to not go over the amperage rating of that header on the motherboard

power pwm gets power form the psu and tac and pwm from 1 fan from the mb and then all the other fans fallow that one fan.

 

it dose not need the voltage form the mb to work becuse its a consted 12v not mater the pwm% i think all it needs is pwm and probably ground but might just need pwm.

Edited November 12, 2022 by thrasher_565

[IkeaGnome]

12 minutes ago, thrasher_565 said:

power pwm gets power form the psu and tac and pwm from 1 fan from the mb and then all the other fans fallow that one fan.

 

it dose not need the voltage form the mb to work becuse its a consted 12v not mater the pwm% i think all it needs is pwm and probably ground but might just need pwm.

It needs the power too. With just power and ground they would spin at 100% all the time. PWM cuts power in pulses to make it spin at the speed you want. The power in a Y splitter comes from the motherboard.

[amsga]

3 hours ago, IkeaGnome said:

They work by getting the PWM signal from the first fan that uses all 4 pins. After that it just assumes they're all the same speed and sends the same pwm speed to all the fans.

 

The only thing to be aware of with them is to not go over the amperage rating of that header on the motherboard

So based on what you mentioned, the motherboard will take the readings off FAN 1 in my diagram and apply the relevant signals, assuming that FAN 2 and FAN 3 works in the same way?

[IkeaGnome]

6 hours ago, amsga said:

So based on what you mentioned, the motherboard will take the readings off FAN 1 in my diagram and apply the relevant signals, assuming that FAN 2 and FAN 3 works in the same way?

That’s correct. They’ll also show in bios and any fan control software as one fan

[thrasher_565]

9 hours ago, IkeaGnome said:

It needs the power too. With just power and ground they would spin at 100% all the time. PWM cuts power in pulses to make it spin at the speed you want. The power in a Y splitter comes from the motherboard.

no it dosent. the pwm is the pulse not the power. its just like argb.

 

 

Edited November 12, 2022 by thrasher_565

[IkeaGnome]

11 minutes ago, thrasher_565 said:

no it dosent. the pwm is the pulse not the power. its just like argb.

Then why bother with pin 2 on PWM fans? What does it do? 
 

Supply power.
You’re trolling right?

[thrasher_565]

2 minutes ago, IkeaGnome said:

Then why bother with pin 2 on PWM fans? What does it do? 
 

Supply power.
You’re trolling right?

the black ground red 12v, yellow tac and blue pwm. but if you pull power from the psu you dont need power from the mb...

[IkeaGnome]

2 minutes ago, thrasher_565 said:

the black ground red 12v, yellow tac and blue pwm. but if you pull power from the psu you dont need power from the mb...

This plugs into the power supply where? there’s a difference between a Y splitter and a fan hub like a Corsair Commander. A splitter is a dumb connector with no outside control. 

[thrasher_565]

10 hours ago, IkeaGnome said:

This plugs into the power supply where? there’s a difference between a Y splitter and a fan hub like a Corsair Commander. A splitter is a dumb connector with no outside control. 

no shi!

[amsga]

14 hours ago, thrasher_565 said:

the black ground red 12v, yellow tac and blue pwm. but if you pull power from the psu you dont need power from the mb...

 

13 hours ago, IkeaGnome said:

This plugs into the power supply where? there’s a difference between a Y splitter and a fan hub like a Corsair Commander. A splitter is a dumb connector with no outside control. 

 

I'm confused now.

I thought by plugging this onto the motherboard, the power would be supplied from the motherboard itself?

 

I thought for 3-pin versions, those only connect to the PSU directly?

[thrasher_565]

1 minute ago, amsga said:

 

 

I'm confused now.

I thought by plugging this onto the motherboard, the power would be supplied from the motherboard itself?

 

I thought for 3-pin versions, those only connect to the PSU directly?

oh sorry to confuse you. there are 2 ways of splitting pwm. one is just a splitor cable that that hooks to the pwm header on the mb and uses it to controll the fans. another way is you get a power pwm hub witch pull power from the psu insted of mb so you could bypass the pwm mb header power limmit. but fans these days are low power anyway so most builds its not needed. in your case a pwm splitor is all thats needed.

 

 

[IkeaGnome]

On 11/11/2022 at 8:21 PM, thrasher_565 said:

power pwm gets power form the psu and tac and pwm from 1 fan from the mb and then all the other fans fallow that one fan.

 

it dose not need the voltage form the mb to work becuse its a consted 12v not mater the pwm% i think all it needs is pwm and probably ground but might just need pwm.

 

5 hours ago, thrasher_565 said:

no shi!

Then where did we start talking about y cable splitters getting power from the power supply?

[thrasher_565]

7 hours ago, IkeaGnome said:

 

Then where did we start talking about y cable splitters getting power from the power supply?

i was taking bout hubs obviously

[IkeaGnome]

4 hours ago, thrasher_565 said:

i was taking bout hubs obviously

It wasn’t obvious and saying that from the start would have fixed a lot of confusion and finger pointing. I can’t read your mind. When you change the subject of the conversation without saying you are you’re the only one that knows you did this.