Question Lost amongst the jargon - - - - fan hub/ splitters for an MSI motherboard ?

[GumDrops]

Hi, I have an MSI Z97I Gaming AC mobo. I know, It's old. But I don't need it for latest games. Just extending its life and it has been working fine for what I need it for. My PC building experience is very weak at best but am giving it a go.

I have had to replace the corsair AIO and I have purchased the DeepCool LE240 V2 AIO. The issue I have encountered is that the Corsair water pump head had a bunch of ports that the fans connected into. The Deepcool does not. And the store staff have not seen pumps like the one I have. Ancient like me 🙂.

The motherboard only has two power connectors. One for the CPU and the other for the sys fan. The front fan connected to the sys fan header and all other fans connected to the Corsair water pump unit. So they recommended I buy a 4 port fan hub which I did. But, then realized upon installation that I have one more fan that I need to connect.

I have asked for a splitter to plug into the hub but they do not have these.

The build has AIO x 2 120mm, case fan 1 x 120mm, rear exhaust 2 x 80mm and the cpu aio pump. So I have five fans to connect to one header. All inside a Corsair Obsidian 250D case. I was thinking to get an air cooler but was told AIO for this case. Not an Air cooler due to restricted space. I can still get an air cooler if that would be a better option and just use the AIO for a new build, which I am going to undertake as soon as I can get this thing running again. (New system will be for my young'n.)

I have been doing some research into Hubs, splitters, power supply, PWM, fan speed control etc but I have come to a point where all this info is getting away from me, so I am seeking some help. The store is now recommending I buy a 6 hub for $32. The 4 port was $9. I am thinking I could just buy another hub and plug it into the other hub? But, does this mean the fans will all run max speeds? I'm pretty confused at this point at what to do. And no, throwing this pc out is not going to happen haha.

So hoping I could get some help in layman's terms minus all the acronyms and jargon.

*Just to add to my waffle I forgot to mention that I had originally thought about taking apart the Corsair AIO pump and adding coolant to it. As it makes a lot of 'bubbling' (for want of a better word) but was advised against this course of action. At the same time, advised to change it out as its signifies that the AIO coolant has run its course.
🙂

 

[Lutfij]

Welcome to the forums, newcomer!

The maximum number of splitters you can have per fan header on your motherboard would be a 1-to-3 splitter.

The build has AIO x 2 120mm, case fan 1 x 120mm, rear exhaust 2 x 80mm and the cpu aio pump. So I have five fans to connect to one header. All inside a Corsair Obsidian 250D case.
I'd side with a fan hub. If all fans are PWM, then you could go with this 5-way PWM fan splitter;
https://akasa.co.uk/update.php?tpl=product/product.detail.tpl&model=AK-CBFA03-45

The store is now recommending I buy a 6 hub for $32.
Mind sharing a link to the hub they're suggesting?

The 4 port was $9.
Link to this?

I am thinking I could just buy another hub and plug it into the other hub?
Please stop.

Come to think of it, are all your fans PWM? If not, then hooking up DC fans to a PWM fan hub would result in DC fans running at full speed.

Might want to wait for the rest of the community to chime in as well.

 

[GumDrops]

I am in the process of trying to understand what PWM stands for. And then trying to work out the difference to the other.
Link to hub

https://www.deepcool.com/products/Accessories/accessories/2021/11375.shtml:)

I haven't seen the other hub. It was a phone conversation at this point.
He wasn't sure whether a hub could go into another hub. :-/

 

[dwd999]

If you can get Amazon where you live they have some 1 to 5 way fan splitters at low prices. Or you could check Alibaba if you prefer that. But be warned that the load of 5 fans all on the 1 sys fan port may be too heavy. If you have a sata power connector available from your power supply a sata powered hub might be better, although it would cost more.

 

[GumDrops]

If you can get Amazon where you live they have some 1 to 5 way fan splitters at low prices. Or you could check Alibaba if you prefer that. But be warned that the load of 5 fans all on the 1 sys fan port may be too heavy. If you have a sata power connector available from your power supply a sata powered hub might be better, although it would cost more.

Thanks for the reply.
Yep, I have been busy making calls and trying to get my head around this. including reading posts on this forum.
From what I have read it appears the sys header outputs 1amp? Not sure if that is the same for all boards?
It was mentioned that I have to figure out the output of my five fans in total and see if that falls under the load limit of the sys header.
Also, i called a couple of other stores outside my area and they said that I can attach a hub into another hub but it is better to just buy an 8 port hub or, use a two way splitter in addition to the 4-port hub. 8 port seems less messy.

 

[Paperdoc]

OK, I can explain and tell you how to connect this new AIO system. First a note, then some background info before details.

NOTE
That AIO system comes with fans and a pump unit that all contain lights of the simpler plain RGB system. For that reason they all have TWO cables from them. In each case there is a cable for the fan MOTOR (or pump motor) and a separate one for the lights. The connectors for the lighting cables are wider than the ones for the motors. To power and control such lights you need a lighting Controller of the correct type and many mobos have those built in. Yours does NOT. So IF you want to use the lights you will need to buy and install a third-party controller. For now I will assume you will NOT use the lights and simply will not plug those cables into anything. If you DO want to pursue using lights, post back here for info on that.

BACKGROUND
Your mobo has two fan headers. The CPU_FAN one next to the CPU chip is guided by the temp sensor built into the CPU chip, so it is the one to use for all items that cool the CPU. That is the pump and rad fans of the AIO system. The SYS_FAN1 one near the board rear middle is guided by a different temp sensor on the mobo, so that is where all your CASE VENT fans are to be connected.

There are two types of devices for connecting more than one fan to a header. A SPLITTER is simple. It connects all of its fans in parallel to the pins of the header, and all power for those fans must come from the header. Normally one header can supply power up to 1.0 A max current to all the fans connected to it. Most modern fans can consume up to 0.2 A max per fan, so it is safe to connect up to 4 common modern fans to one header using a Splitter, BUT you must actually check the fan specs (on its label) for the real max current Amps. A Splitter has one "arm" to plug into the host header on the mobo, and two or more output "arms" for plugging in your fans. It has NO other connection. A HUB is different in this item: although it has those input and outputs, it ALSO has a third "arm" that goes to a power output connector from the PSU. This device gets info from the host header but does NOT draw any power from it, so the 1.0 A max limit does NOT apply. A Hub gets all fan power from the PSU directly. But a HUB can work only with the newer 4-pin PWM style fan, and only with a host header that is sending out signals in that PWM Mode. As it happens, the manual for your mobo indicates that both of your headers do ONLY that PWM Mode of signals, so you CAN use a Hub with 4-pin fans. Both Splitters and Hubs may look the same. Some look like collections of cable arms; some like a small printed circuit board; and some like a closed box with output sockets recessed in holes. So appearance does not tell you. And sellers often use the two terms as if they are the same thing, and they are NOT. The distinctive item is that a HUB must have that third connection to a PSU power output. You should look closely at the Hub you bought. IF it has some connection to the PSU, then it is a Hub. If not, it is a Splitter.

Any fan sends back to its host header via Pin #3 a speed signal consisting of a train of pulses to be counted. Any header can deal with such a pulse train from only ONE fan. So any Splitter or Hub will send back to its header the speed signal of only ONE of its fans and ignore the rest. The speed of those "other" fans will never be seen anywhere. This has NO impact on ability to control the fan speeds. Every fan header also does a second job: it monitors the speed signal it receives for NO signal, indicating the fan has FAILED. If that happens it will pop up a warning on your screen. But on many mobos the CPU_FAN header will take more drastic action. If it gets no speed signal it may shut down your whole system as a means of protecting the valuable CPU chip from overheating due to NO cooling, and may not allow you to boot up if that header gets no speed signal immediately after power is turned on. So when you use a Slpitter or Hub it is important to plug one fan into the ONLY output that does send back the speed signal. For units that look like a collection of cable arms. only ONE of the outputs will have all 4 pins, and the others will be missing Pin #3 so they can not send back the speed signal from those fans. On other types of units, one output will be marked in some way as the only one that can send back its speed signal. NOTE that, becasue a Splitter or Hub cannot report the speed of ALL of its fans, they cannot ALL be montored for failure. So from time to time YOU should just look to verify that all fans still are working.

Because of the details of fan motor design, the speed of an older 3-pin fan can be controlled only by reducing the Voltage supplied to it from Pin #2. But the newer PWM design works differently and is fed the full 12 VDC supply from Pin #2 always. Then it also gets the PWM control signal from Pin #4 and uses that with its special chip to control its own speed. So IF you plug an older 3-pin fan into a header providing signals in the new 4-pin PWM Mode, that fan will always run full speed.

DETAILS FOR YOU - HOW TO CONNECT
You WILL need one Splitter for this. Here's an example of a two-pack of simple "collected cables" Splitters

https://www.amazon.com/Splitter-Header-Converter-Computer-Cooling/dp/B0D53G6133/ref=sr_1_10?crid=2VOJAB50QT3Q5&dib=eyJ2IjoiMSJ9.pOdXzAFQGUEN0PKZR2F_H7yoVEFAjWDHYstEgegv1sPEuOMca3KUoJO15ne5Bir5pM6R2eArr63cN2u1tJSZC47-tnwlClpKxaiiA0USvdJkqdMrMY7NVOoSW9cwE5YKJ98pWGjFql_1MlgjOxmNvM4ZezdlpTz22T60XxprRENLzqB9JFcdZvzf17OZtphbVCMR1fWVeopDvw23gcpNlnIXd3KwR15HOsSMNLAFJ04.g4N69Ih_RvcCMgY3ncLOKGyMlD1vjW8mGwpSaTOslCk&dib_tag=se&keywords=fan+splitter+4+pin&qid=1750484450&sprefix=fan+splitter,aps,123&sr=8-10

See what I mean? One input, three outputs, NO extra connection to the PSU. ONE output has 4 pins, the others are missing Pin #3.

You need this for the AIO system that cools the CPU. That system has three components that need power and control: the pump, and two rad fans. And we will use a "trick". This system is designed to have the PUMP unit run full speed all the time, and all control of CPU cooling is done by altering the speed of the two rad fans. The PUMP unit actually is wired just like an older 3-pin fan, and so its motor connector has only THREE holes. But it WILL plug into a 4-pin output. So we can connect that pump AND both rad fans together using a Splitter to the CPU_FAN header in a particular way. Plug the PUMP motor cable into the only Splitter output with all 4 pins so that the PUMP speed is sent back to the header. Plug the two rad fans each into the other Spltter outputs. (Doing this does not make use of the extra connector on each fan motor.) Why this way? Because in this system the most critical component to monitor for FAILURE is the PUMP. No pump operation means no fluid flow to carry heat over to the rad. On the other hand, even if both rad fans failed, another system would detect a slow increase in CPU temperature and take a different action to protect the CPU. When you connect this way the PUMP gets a constant 12 VDC power supply and runs full sped always, as designed. The two Rad Fans get that same power BUT also receive the PWM signal from Pin #4. Their speeds ARE controlled by the CPU_FAN header. The total max current load for these three items is 0.54 A, well less than the header limit.

Now to the case ventilation fans - three of them in your plan. Although you have not told us their details, it is likely that their combined total max Amps is less than 1.0 and hence you could use the other Splitter for them. But you already have a Hub, so you might just as well use that. Connect that to the SYS_FAN1 header and plug in your case fnas, ensuring that one of those is plugged into the identified special outpout port so a fan speed is reported to the SYS_FAN1 header.

 

[GumDrops]

OK, I can explain and tell you how to connect this new AIO system. First a note, then some background info before details.

NOTE
That AIO system comes with fans and a pump unit that all contain lights of the simpler plain RGB system. For that reason they all have TWO cables from them. In each case there is a cable for the fan MOTOR (or pump motor) and a separate one for the lights. The connectors for the lighting cables are wider than the ones for the motors. To power and control such lights you need a lighting Controller of the correct type and many mobos have those built in. Yours does NOT. So IF you want to use the lights you will need to buy and install a third-party controller. For now I will assume you will NOT use the lights and simply will not plug those cables into anything. If you DO want to pursue using lights, post back here for info on that.

BACKGROUND
Your mobo has two fan headers. The CPU_FAN one next to the CPU chip is guided by the temp sensor built into the CPU chip, so it is the one to use for all items that cool the CPU. That is the pump and rad fans of the AIO system. The SYS_FAN1 one near the board rear middle is guided by a different temp sensor on the mobo, so that is where all your CASE VENT fans are to be connected.

There are two types of devices for connecting more than one fan to a header. A SPLITTER is simple. It connects all of its fans in parallel to the pins of the header, and all power for those fans must come from the header. Normally one header can supply power up to 1.0 A max current to all the fans connected to it. Most modern fans can consume up to 0.2 A max per fan, so it is safe to connect up to 4 common modern fans to one header using a Splitter, BUT you must actually check the fan specs (on its label) for the real max current Amps. A Splitter has one "arm" to plug into the host header on the mobo, and two or more output "arms" for plugging in your fans. It has NO other connection. A HUB is different in this item: although it has those input and outputs, it ALSO has a third "arm" that goes to a power output connector from the PSU. This device gets info from the host header but does NOT draw any power from it, so the 1.0 A max limit does NOT apply. A Hub gets all fan power from the PSU directly. But a HUB can work only with the newer 4-pin PWM style fan, and only with a host header that is sending out signals in that PWM Mode. As it happens, the manual for your mobo indicates that both of your headers do ONLY that PWM Mode of signals, so you CAN use a Hub with 4-pin fans. Both Splitters and Hubs may look the same. Some look like collections of cable arms; some like a small printed circuit board; and some like a closed box with output sockets recessed in holes. So appearance does not tell you. And sellers often use the two terms as if they are the same thing, and they are NOT. The distinctive item is that a HUB must have that third connection to a PSU power output. You should look closely at the Hub you bought. IF it has some connection to the PSU, then it is a Hub. If not, it is a Splitter.

Any fan sends back to its host header via Pin #3 a speed signal consisting of a train of pulses to be counted. Any header can deal with such a pulse train from only ONE fan. So any Splitter or Hub will send back to its header the speed signal of only ONE of its fans and ignore the rest. The speed of those "other" fans will never be seen anywhere. This has NO impact on ability to control the fan speeds. Every fan header also does a second job: it monitors the speed signal it receives for NO signal, indicating the fan has FAILED. If that happens it will pop up a warning on your screen. But on many mobos the CPU_FAN header will take more drastic action. If it gets no speed signal it may shut down your whole system as a means of protecting the valuable CPU chip from overheating due to NO cooling, and may not allow you to boot up if that header gets no speed signal immediately after power is turned on. So when you use a Slpitter or Hub it is important to plug one fan into the ONLY output that does send back the speed signal. For units that look like a collection of cable arms. only ONE of the outputs will have all 4 pins, and the others will be missing Pin #3 so they can not send back the speed signal from those fans. On other types of units, one output will be marked in some way as the only one that can send back its speed signal. NOTE that, becasue a Splitter or Hub cannot report the speed of ALL of its fans, they cannot ALL be montored for failure. So from time to time YOU should just look to verify that all fans still are working.

Because of the details of fan motor design, the speed of an older 3-pin fan can be controlled only by reducing the Voltage supplied to it from Pin #2. But the newer PWM design works differently and is fed the full 12 VDC supply from Pin #2 always. Then it also gets the PWM control signal from Pin #4 and uses that with its special chip to control its own speed. So IF you plug an older 3-pin fan into a header providing signals in the new 4-pin PWM Mode, that fan will always run full speed.

DETAILS FOR YOU - HOW TO CONNECT
You WILL need one Splitter for this. Here's an example of a two-pack of simple "collected cables" Splitters

https://www.amazon.com/Splitter-Header-Converter-Computer-Cooling/dp/B0D53G6133/ref=sr_1_10?crid=2VOJAB50QT3Q5&dib=eyJ2IjoiMSJ9.pOdXzAFQGUEN0PKZR2F_H7yoVEFAjWDHYstEgegv1sPEuOMca3KUoJO15ne5Bir5pM6R2eArr63cN2u1tJSZC47-tnwlClpKxaiiA0USvdJkqdMrMY7NVOoSW9cwE5YKJ98pWGjFql_1MlgjOxmNvM4ZezdlpTz22T60XxprRENLzqB9JFcdZvzf17OZtphbVCMR1fWVeopDvw23gcpNlnIXd3KwR15HOsSMNLAFJ04.g4N69Ih_RvcCMgY3ncLOKGyMlD1vjW8mGwpSaTOslCk&dib_tag=se&keywords=fan+splitter+4+pin&qid=1750484450&sprefix=fan+splitter,aps,123&sr=8-10

See what I mean? One input, three outputs, NO extra connection to the PSU. ONE output has 4 pins, the others are missing Pin #3.

You need this for the AIO system that cools the CPU. That system has three components that need power and control: the pump, and two rad fans. And we will use a "trick". This system is designed to have the PUMP unit run full speed all the time, and all control of CPU cooling is done by altering the speed of the two rad fans. The PUMP unit actually is wired just like an older 3-pin fan, and so its motor connector has only THREE holes. But it WILL plug into a 4-pin output. So we can connect that pump AND both rad fans together using a Splitter to the CPU_FAN header in a particular way. Plug the PUMP motor cable into the only Splitter output with all 4 pins so that the PUMP speed is sent back to the header. Plug the two rad fans each into the other Spltter outputs. (Doing this does not make use of the extra connector on each fan motor.) Why this way? Because in this system the most critical component to monitor for FAILURE is the PUMP. No pump operation means no fluid flow to carry heat over to the rad. On the other hand, even if both rad fans failed, another system would detect a slow increase in CPU temperature and take a different action to protect the CPU. When you connect this way the PUMP gets a constant 12 VDC power supply and runs full sped always, as designed. The two Rad Fans get that same power BUT also receive the PWM signal from Pin #4. Their speeds ARE controlled by the CPU_FAN header. The total max current load for these three items is 0.54 A, well less than the header limit.

Now to the case ventilation fans - three of them in your plan. Although you have not told us their details, it is likely that their combined total max Amps is less than 1.0 and hence you could use the other Splitter for them. But you already have a Hub, so you might just as well use that. Connect that to the SYS_FAN1 header and plug in your case fnas, ensuring that one of those is plugged into the identified special outpout port so a fan speed is reported to the SYS_FAN1 header.

Thanks for taking the time to write such a comprehensive reply Paperdoc. That was outstanding.
I've been reading through it a few times and will put together a (hopefully) decent reply with pics.
Cheers.

 

[GumDrops]

Apologies for the late reply. I've been occupied with a sick daughter :-/

You are correct. I am not interested in the RGB lights.
I have re-read your in-depth reply and believe I have the gist of it now. 🙂

These are the parts that I have;
2x Noctua 80mm rear fans 0.06A ech
https://www.quietpc.com/nf-r8-pwm

1x Corsair 120mm front fan 0.25A
https://www.corsair.com/us/en/p/cas...dition-high-static-pressure-fan-co-9050013-ww

2x Deepcool 120mm AIO fans 0.17A ech

Total = 0.71 A
(Excludes Pump of which I have attached to the cpu header)

The FH-04 Deepcool HUB has only one cable coming from it. (And if I understood what you have said this is in fact a splitter.)

With the AIO there is one accessory cable. It has one input and two outputs. A 4 pin and a 3 pin.
However the pamphlet and website show that it should have three outputs, not two.
So perhaps a mistake by the factory?

Where I live none of the PC stores in an 80 k radius have splitters or hubs except the one I was sold. Not even Jaycar.
So I will need to order online.
None of the stores I had called could help me with any information. Quite dis-heartening really.


Forgot to add these two links that I am looking at. I don't think there is a difference except one has an extra output?

https://www.legendpc.co.nz/LPC-1-To-3-Way-Fan-Y-Splitter-Sleeved-4-Pin-3-Pin-PWM-Fan-Extension-Cable

https://computerlounge.co.nz/products/arctic-4-pin-pwm-fan-splitter-cable

 

[Paperdoc]

Based on that additional info I can advise a few small adjustments.

1. The RAD FANS from the AIO system need to be connected to the CPU_FAN header. That is the only header on your mobo that alters the fan speeds according to the temp sensor inside the CPU. That is why I said you need a Splitter to connect those two fans AND the PUMP to the CPU_FAN header.
2. You are right: that Deepcool FH-04 unit is a SPLITTER, not a Hub. So your simple solution is to buy one more of those locally. (Deepcool also sells a different unit, the FH-10, that is a Hub. Do NOT get one of those.) Use one for the AIO system to CPU_FAN, and the other to connect your three case fans to SYS_FAN1. In that Splitter box, the specs say that ONLY the output marked FAN1 will send its speed signal back o the host header. So for the AIO system, connect the PUMP's motor cable to FAN1 and the two Rad Fans' cables to the next ports. For the three case fans, just ensure that any one of them is plugged into the FAN1 port of their FH-04 unit.
3. The accessory cable with the AIO system that you mention is intended to use to connect the two Rad Fans to one mobo fan header according to the manual sheet. See item 10 on that sheet. BUT that assumes you do have a separate header like CPU_OPT for that connection, and your mobo does not. The easy path then is NOT to use that cable., Simply connect those two Rad Fans to the FH-04 Splitter box you use for the entire AIO system.

This may not apply, but SOME Corsair case fans had a small three-position switch in their power cables to allow you to slow them down. IF you have this, just set it to max speed and let the mobo header do a;l fan speed control.

Best wishes to you and your daughter for her speedy recovery.

 

[GumDrops]

Beautiful, thank you to everyone for their help and for the explanations and the tutorial.
I will get this second Deepcool FH-04 today and fire this thing up and see how it goes.
During its idle state I added some faster ram and an I7-4790K I got from someone just to give it a bit more life.
Will be interesting to see if it starts first go without a hitch 😎

 

[GumDrops]

Everything went well. Temps are great 30c
Now onto configuring the ram, cpu and bios.
Cheers, I'm not sure I'd have figured this out on my own.
It would have taken a lot longer in any case so bug thanks.

 

[Paperdoc]

Thanks for the update, and good to hear it is working. We all come here to learn and to help others by passing on that learning.