Question Multiple case fans and pumps on ITX motherboard...

[SashimiSensei]

Hi all,

I have an ITX setup in the Fractal Design Define Nano S with an i5-6600K and a Zotac 1070ti Mini GPU. Currently, the GPU is getting up to about 82-83 degrees while gaming, which is way too hot for my liking. I've bought the NZXT Kraken G12 and a Corsair H55 AIO, which I want to use on the GPU. However, my motherboard is the MSI Z170i Gaming Pro AC, which only has a single PWM fan header - designated as the CPU header. The other fan header on the Mobo is "SYSFAN1" and is described in the manual as being a "Voltage Mode" header.

So, before I start tearing the GPU apart and making my Frankenstein, does anyone have any advice on how to connect all the fans and pumps?

I feel I should keep my CPU cooler fan (DarkRock 3) plugged into the Mobo CPU header? But then where do I plug in the AIO for the GPU, plus the remaining case fans? Can the AIO pump be connected to this SYSFAN1 header, or will that make it run at 100% constantly?

Could I buy a fan controller like this and plug the AIO into that? Or is that a terrible idea? I don't know! Any advice would be greatly appreciated.

Sashimi.

 

[CountMike]

Well, yes, a controller with multiple connections is your only solution, Just leave CPU cooler fan at it's normal place, the rest could be controlled by that or other controller.

 

[Paperdoc]

To summarize, you plan to improve cooling of your graphics card by replacing its fan and heatsink system with a third party AIO liquid cooler from Corsair, their H55 system, held onto the graphics card by a NZXT Kraken G12 adapter system. What you need is both power for that cooler and control of it.

First, recognize that in almost all cases (including yours), power and control of cooling on the graphics card is NOT provided by the mobo at all. The graphics card itself does those jobs. But your mobo does provide power and control of cooling systems for its CPU (via its only CPU_FAN header), and for the case ventilation fans via its one SYS_FAN header which can only operate in the older Voltage Control Mode. The mobo facilities you have are sufficient for those two jobs. You have not told us details of the CPU cooler, but you are not worried abut that and I assume it is connected to the CPU_FAN header and working well. Your case came with front and rear 3-pin fans and some sort of adapter. I am going to assume those fans are both connected to the SYS_FAN1 header and operating properly also. None of that needs to change.

Your graphics card came with two fans and a heatsink system pre-mounted which you will remove. I am sure the fans are connected to one or two sockets on the graphics card that provide both power and speed control of the fans. Most commonly the method of control of those fans also is Voltage Control just like any case 3-pin fan, but we don't have complete specs to verify that. You should inspect those connections now. One VERY important item for that is the details of the connectors on the ends of each fan's wires, and hence of the socket in the graphics card that they plug into. IF there are THREE wires to each fan, and IF the connectors on their ends are the SAME as standard 3-pin case fan connectors, then it is likely the system involved is the same as any older-style mobo 3-pin fan system. If that is not what you find, post back here what IS there.

What I am hoping is that the graphics card's fan control socket(s) are just common 3-pin fan systems so they can be used to provide both power and control for two items in your new system. That new system has three electrical components to consider. The H55 system has a PUMP and a radiator FAN. Both of these are wired electrically like common 3-pin fans. The pump is different from a fan, though, in an important factor. It is intended to run at full speed all the time, so it needs a constant 12 VDC power source (and ground), but does NOT need varying voltage to control its speed. So you can provide the power for the pump unit by using a simple adapter to connect it to a 4-pin Molex PSU output connector, like this:

https://www.newegg.com/black-en-lab...lex_to_fan_adapter-_-9SIACJF76E4306-_-Product

So the pump does not need any connection to a fan header on either the mobo or the graphics card. Then the H55 system has a 3-pin fan mounted on its radiator. Plus, the Kraken G12 mounting system comes with a pre-mouted 3-pin fan of its own to cool some components of the graphics card other than the main GPU chip. Thus you have TWO 3-pin fans that require power AND control of their speeds governed by the cooling requirements of the Graphics card itself. Such control can be provided ONLY the the graphics card, not by the mobo, and the card already DOES do that job for its included two fans. The only missing piece of info here is whether the electrical signals available from the card for its original two fans can be adapted to the two fans of your new system. The new fans are "standard" 3-pin fans, so IF the graphics card's original fans also were of that type, there is no real problem. IF the sockets on the card also are "standard" 3-pin male fan sockets, just plug in there. IF there were TWO such sockets on the cards, great and easy! IF there was only one, you might need a simple 3-pin fan Splitter like this

https://www.newegg.com/p/N82E168124...ter&cm_re=fan_splitter-_-12-423-168-_-Product

That would get you power for those two fans AND automatic control of their speed by the graphics card based on the cooling needs of that card. In fact, usually the software tools provided with such a card include some ways to observe and configure (maybe set custom cooling control of) the graphics card. None of this depends on mobo fan headers.

 

[SashimiSensei]

Thanks for the detailed reply Paperdoc.

I didn't actually know that the AIO pump would need to be running at 100% all the time, I just assumed it would ramp up/down as needed, so that is good information to know!

I'll have to have a dig around at the GPU and see what kind of fan connections it has. Am I right to assume though, that should the headers on the GPU are not standard 3-pin male headers, I could always hook them up to the SYSFAN1 and have them controlled via Voltage Control?

 

[Paperdoc]

Well, MAYBE. The real problem there is that the control system that determines what signals the SYS_FAN header sends out is based in trying to keep the temperature measured at a sensor on the MOTHERBOARD at the right target. That has VERY little relationship to the cooling needs of the GPU chip or of any other component of the graphics card. In fact, IF you cannot arrange to have the graphics card cooling system you add controlled by the existing system ON THE GRAPHICS CARD, your better option would be to connect both the new fans to a constant full 12 VDC power source from the PSU, just as the Pump unit will be. Constant too much cooling on the graphics card is certainly better than having it too little and unrelated to the card's real cooling needs.

It can be almost impossible to find a source of information telling you what electrical signals are being sent by the card to its existing pair of fans. But you might try to figure that out yourself. Whether the fans are fed via one or two sockets on the graphics card, or by hard-wired connections to the board, using a voltmeter you could determine what voltage is supplied to the fans, and the polarity of that. IF the fans each have three wires, one of them will be its speed signal. On a common 3-pin case fan the wires are coded as:
Pin #1 - Ground - Black
Pin #2 - Red - +VDC varying 5 to 12 volts
Pin #3 - Yellow - speed pulse signal - cannot read with a voltmeter
So if you're lucky you will find the same on the graphics card's existing fans, even if the wire colours are not the same. IF the fans have 4 wires from each, that's more difficult. IF they have only two wires each, VERY likely they are the + and - (Ground) of the varying supplied voltage.

If it runs out that you have "standard" 3-pin fan signals on the existing fans' wires, you can figure out how to connect those outputs from the card to the new fans you install. Just a note on this. There are some small fans designed for 5 VDC supply, not 12. So the RANGE of the voltages reaching the existing fans is important, because the two new fans you propose to add are designed for a max 12 VDC supply, and normally would not be sent anything below 5 VDC to avoid having them stall.

There MIGHT be another factor to consider in making these new connections. IF the existing fans on the card do send their speed signals back to that card, it MAY be monitoring those signals for FAILURE, as well as displaying their speed. In that case it is possible that NO speed signal to the card might cause it to shut down to prevent overheating of the GPU due to presumed failure of the cooling fans. That depends on how the card was designed, and on whether the fans really do have a third wire to send out their speeds.