What is a fan hub and what does it do?

[The Xilent Penumbra]

So I've ordered a bunch of parts for my first build, now waiting for them to arrive so I'm taking the time to plan out and learn some minute detail that I may have missed... Something that I couldn't get my head around are fan hubs. My mobo is the msi Z97 Gaming 5 and my case is the NZXT Noctis 450. I know that my case has an 8 port PWN fan hub and since it's the first thing that's advertised on the product page it must be kind of a big deal. My understanding of it is that I somehow plug the fan hub into my mobo (somewhere I don't know) which allows me to plug a bunch of fans into the fan hub and have more fans overall and maybe have more control over their speeds. I don't know if that is correct though. If all you nice people on Tom's Hardware could explain to me the uses, benefits, drawbacks, how to use the fan hub and variation in them I would be very thankful to everyone that helps out. I can provide any other details if needed but I don't think my CPU will be needed to answer this (4690k if you must know).

Thank you in advance.

 

[getochkn]

Yes, it gives you more ports and is usually externally powered by your PSU.

A normal fan connector on a motherboard can handle a few fans before it draws too much power and can short the board, so if you want 8 fans, that is too much for a single fan header and a fan splitter. So with a hub, it sends the speed info to the motherboard and allows the motherboard to control the speed, but the power is provided direct from your PSU so it doesn't blow your board by drawing too much power.

 

[dhaan]

At the back of the mobo tray there will be a hub with 8 fan connectors where you can plug them all in this is for easier cable managment.

 

[The Xilent Penumbra]

So basically I will plug in a cable from the hub into my mobo for control and another cable into the PSU for power?

 

[dhaan]

Yes

 

[The Xilent Penumbra]

oh that was easier than I thought it would be, does anyone know what connectors go where or will I have to wait till my case arrives so I can have fun reading paragraphs and paragraphs in the manual. I think theres a molex connector for power maybe but not sure but what goes into the mobo

 

[dhaan]

There will be a fan cable connected to the hub just connect it to the mobo

 

[The Xilent Penumbra]

There will be a fan cable connected to the hub just connect it to the mobo

do i plug it into the same port as if i was to not use the hub... if so wouldnt that draw power from it somehow or is it made to not draw power specifically for this kind of setup?

 

[getochkn]

They're usually made to not draw power, IE, the power pins aren't even there on the connector. IT's normally a 3 or 4 pin connector, well these will 1 or 2 pins. Power and ground are left out.

 

[dhaan]

I took a look at the case it does not use external power it just splits 1 fan connector to 8

sorry my bad it does use external power should have looked better

 

[The Xilent Penumbra]

ok so to clarify, I will plug in a cable from the hub to the PSU for power and another cable will go from the hub into a fan header(i think that's what it's called) on my mobo. This will let me have more fans in my case without increasing the risk to short my mobo and I will still be able to control my fans using the mobo BIOS or apps that can do this wizardry. Am I right?

 

[dhaan]

yes that is correct

 

[The Xilent Penumbra]

Thank you both getochkn and dhaan, this really cleared it up.

 

[Paperdoc]

Which mobo fan port you plug into is important. Your mobo has two CPU_FAN ports plus three SYS_FAN ports. I REALLY recommend you connect your CPU cooling system to the mobo's CPU_FAN port and allow it to control the CPU fan automatically.

After that you have your case fans. Since your case comes with a PWM fan hub, you probably can connect all the case ventilation fans to that hub, and it will control them all using the PWM signal it gets from the mobo port you plug it into. I suggest that should be the SYS_FAN1 port. It should NOT be the CPU_FAN port, even if you see that suggested in some places.

Be aware that ALL of the fans you plug into that hub MUST be of the 4-pin type (PWM Control Mode). That hub cannot exercise any speed control over 3-pin (Voltage Control Mode) fans.

The hub draws all power for its fans directly from the PSU through one connector. It gets the PWM control signal for all its fans from one mobo fan port and just passes that on to all its fans. (A fan places almost no load demand on the PWM signal line, so whatever the mobo port provides CAN be shared with many fans.) The hub usually also does one more thing. It accepts the speed pulse signal coming back to it from ONE of its fans (usually one connected to a particular identified port, like #1) and passes that back to the mobo port it is connected to. None of the other hub fans can send its speed signal anywhere, so you will never read those speeds.

 

[Deanix]

Which mobo fan port you plug into is important. Your mobo has two CPU_FAN ports plus three SYS_FAN ports. I REALLY recommend you connect your CPU cooling system to the mobo's CPU_FAN port and allow it to control the CPU fan automatically.

After that you have your case fans. Since your case comes with a PWM fan hub, you probably can connect all the case ventilation fans to that hub, and it will control them all using the PWM signal it gets from the mobo port you plug it into. I suggest that should be the SYS_FAN1 port. It should NOT be the CPU_FAN port, even if you see that suggested in some places.

Be aware that ALL of the fans you plug into that hub MUST be of the 4-pin type (PWM Control Mode). That hub cannot exercise any speed control over 3-pin (Voltage Control Mode) fans.

The hub draws all power for its fans directly from the PSU through one connector. It gets the PWM control signal for all its fans from one mobo fan port and just passes that on to all its fans. (A fan places almost no load demand on the PWM signal line, so whatever the mobo port provides CAN be shared with many fans.) The hub usually also does one more thing. It accepts the speed pulse signal coming back to it from ONE of its fans (usually one connected to a particular identified port, like #1) and passes that back to the mobo port it is connected to. None of the other hub fans can send its speed signal anywhere, so you will never read those speeds.

I don’t know if you’re still around as this is an old thread but I wanted to thank you for your detailed comment. It helped me learn what I wanted and I appreciate it.