What are all pins on a 4 pin PWM fan responsible for?

[shanetemple14]

Title is self explanatory, can someone tell me what all the 4 pins are for on a PWM fan? I currently have 2 intake and 1 exhaust fan hooked up to my PC using a molex to 3 way fan splitter (2 pin header I believe).

At the moment all of my fans (Fractal design Dynamic X2 GP-12) are running at full speed because they cannot receive instruction from my MOBO of when to speed up/down.

I would like to buy a fan hub that I see utilizes 3 pin headers on the hub, so what is the 3rd pin for and what extra functionality would the 4th pin add? (I realize my fans are 3 pin connectors which is why i'm looking at a 3 pin header hub).

Thanks in advance

 

[Dark Lord of Tech]

http://www.pavouk.org/hw/fan/en_fan4wire.html
4-Wire fans

 

[shanetemple14]

http://www.pavouk.org/hw/fan/en_fan4wire.html
4-Wire fans

So the third pin ONLY READS the information but does nothing with it? How come if i plugged that fan into my motherboard (3pin fan to a 4pin mobo header) the fan will dynamically change speeds?

 

[Mr5oh]

http://www.pavouk.org/hw/fan/en_fan4wire.html
4-Wire fans

So the third pin ONLY READS the information but does nothing with it? How come if i plugged that fan into my motherboard (3pin fan to a 4pin mobo header) the fan will dynamically change speeds?

The speed can still be changed by adjusting the voltage to it.

 

[shanetemple14]

http://www.pavouk.org/hw/fan/en_fan4wire.html
4-Wire fans

So the third pin ONLY READS the information but does nothing with it? How come if i plugged that fan into my motherboard (3pin fan to a 4pin mobo header) the fan will dynamically change speeds?

The speed can still be changed by adjusting the voltage to it.

I take it that would be done within the BIOS and would not be possible with a device such as the Phanteks PWM fan hub?

From what I understand at the moment the hub is literally just a way to easily power many fans and not actually change the speeds on the fly without user input.

 

[Darkbreeze]

No, that's not accurate. Not if you're talking about the PWM hub that comes with the cases. The Phanteks hub controls via the PWM signal off the single four pin cable that connects the hub to the motherboard. Signal is not needed from each individual fan.

RPM signal is read from the fan that is plugged into FAN_1 on the PWM hub and all the other fans plugged into the hub will be controlled based on the reading from that one input.

Phanteks also has a user controlled manual hub that has no relation to anything except the variable voltage provided by the controller knob on that style hub/controller unit.


One looks like this, and is controlled via PWM signal from the FAN_1 header on the hub:

And actually I can't find ANY strictly voltage controlled manual Phanteks hubs. The other hub they have which is much like the NZXT Grid+ v2 connects to and is controlled by the CPU temperature as read through the internal USB 2.0 header. That one looks like this:

 

[shanetemple14]

No, that's not accurate. The Phanteks hub controls via the PWM signal off the single four pin cable that connects the hub to the motherboard. Signal is not needed from each individual fan.

RPM signal is read from the fan that is plugged into FAN_1 on the PWM hub and all the other fans plugged into the hub will be controlled based on the reading from that one input.

Okay thats more what I thought of in the first place. So my original plant to connect my case fans to the hub so that they change speeds on their own (compared to the full 12v speed currently) will work?

 

[Darkbreeze]

I modified my earlier post. Might want to take another look at that. I would highly recommend the NZXT Grid+ v2 or v3. I think the v3 is a better unit and offers some options and features not found on the v2. I have the v2 which does not work correctly with PWM fans connected to the 3 pin headers on the hub. The v3 does work with 4 pin PWM fans OR with 3 pin voltage controlled fans, and both connect to the motherboard via internal USB header.

It allows you to monitor and custom curve your fans any way you like through the CAM software. I've had zero issues with my unit. The only reason I even used this is because I dislike not have the ability to set custom fan curves graphically in the bios on my Z170x-Gaming 5 and the presets in the bios would not allow fan operation below 40%. With the Grid+ I can set them for only 20% operation at their lowest settings and can create profiles for them to increase speed at each five degree interval that I wish to.

I haven't looked at the Phanteks version of it, but I'd assume it's somewhat similar. Looks like almost the exact same thing. I'd be surprised if it wasn't pretty much identical.

 

[shanetemple14]

I modified my earlier post. Might want to take another look at that. I would highly recommend the NZXT Grid+ v2 or v3. I think the v3 is a better unit and offers some options and features not found on the v2. I have the v2 which does not work correctly with PWM fans connected to the 3 pin headers on the hub. The v3 does work with 4 pin PWM fans OR with 3 pin voltage controlled fans, and both connect to the motherboard via internal USB header.

It allows you to monitor and custom curve your fans any way you like through the CAM software. I've had zero issues with my unit. The only reason I even used this is because I dislike not have the ability to set custom fan curves graphically in the bios on my Z170x-Gaming 5 and the presets in the bios would not allow fan operation below 40%. With the Grid+ I can set them for only 20% operation at their lowest settings and can create profiles for them to increase speed at each five degree interval that I wish to.

I haven't looked at the Phanteks version of it, but I'd assume it's somewhat similar. Looks like almost the exact same thing. I'd be surprised if it wasn't pretty much identical.

Ok, I will take a look at the NZXT V3, thank you

 

[Darkbreeze]

Phanteks:

NZXT Grid+ v2:

 

[shanetemple14]

Just to clarify you recommend the v3 more than the v2 right?

 

[Darkbreeze]

Yes. It's the v2 but improved. I don't think the v3 is available anywhere except through NZXT YET. Should be soon if it's not already but I don't see it anywhere else. Any of them will probably work for you though. I think I recall that possibly the issues using PWM fans on the v2 was resolved through firmware but you'd want to verify that first.

Personally, I'd recommend the v3 as a better product though. They don't release new products unless there is a clear reason why a revision was necessary and when they do they are generally equipped with better electronics and features. Not always, but usually.