Question Need Help Setting Up Auto Fan Control Water Cooled GPU For My First Build.

[REXYON]

Its my first build and Im trying to figure out how to automatically control the fan speed based on the cards temps on a Alphacool Eiswolf 2 running an Asus Rog Strix 4090 OC, on a MSI Z790 GODLIKE motherboard with a 14900k as im not sure which fan connection to use and the settings needed on the bios/board etc. I have the radiator/fans running on the pump fan connector but they are on at 100% and I plan on setting a power limit on the gpu to 300W or lower while I work on audio in Nuendo. Appreciate any help. Thanks

 

[Lutfij]

Welcome to the forums, newcomer!

For the sake of relevance, can you pass on a link to your AAIO, since there are instances of the AIO being paired with a standalone waterblock off of Alphacool's portfolio. On a side note, can you pass on what you see as options for fan control in BIOS for the pump header or all fan headers(within BIOS)?

Using this manual;
https://download.alphacool.com/manu...7900XTX_Merc_310_with_Backplate_Manual(2).pdf
as a template for the fans and pump. Hook the pump for the AIO to the 2nd pump header(designated PUMP_FAN2) on the motherboard, while the fans are on a splitter/y-cable that's hooked to any PWM fan header on the motherboard.

Just c curious, what are you cooling the processor with? If your entire build watercooled, then please give us a picture of your cooling loop as well as how the rest are hooked up tot he system besides what you've state with the GPU.

 

[Paperdoc]

You are looking for the wrong thing, and the process is NOT obvious because these are non-"standard" pieces.

The root of this all is: there has never been any "standard" way for an added video card to send out to the mobo its fan speed control signal, or even its GPU chip temperature. ALL video cards do GPU cooling control entirely by themselves. All video card makers include with their cards a software utility used to observe and adjust many card parameters, including tuning up the cooling system on the card. These include ability to see cooling fan speeds and adjust them, and GPU chip temperature. But that does NOT feed that info out to any other device, nor to the mobo.

I would PRESUME that the AIO system you plan to use is designed very similarly to ones for a CPU on a mobo. In virtually all of those systems, the PUMP is supposed to receive a fixed 12 VDC power supply and run at full speed all the time. ALL control of CPU cooling is done by varying only the speed of the rad fans. IF your video card AIO system works that way, then you only need to find how to control its rad fans' speeds.

So, how do YOU "tap into" that info to provide automatic control of an EXTERNAL cooling system? There are two possible paths in theory. The simplest is to access somehow the signal on the card that controls the SPEED of the card's built-in fans, and let the card's CONTROL system do all the "thinking". On many cards that appears to be not too difficult because the card fans all plug into what looks like a standard computer case fan header. Usually that has 4 pins as a newer PWM Mode mobo fan header would, and the fans appear also to be "standard" 4-pin PWM fans. BUT the appearances do NOT guarantee that is how those card fans are run, so YOU have to investigate and verify that really IS how the card fans are powered and controlled. Then you might arrange simply to connect your new AIO system rad fans to that video card fan header. That MAY involve a custom connector and wiring the right wires to the right contacts. It also WILL involve YOU having to find the right settings to enter into the video card's cooling control system to operate this different cooling system and achieve proper GPU cooling.

BUT again, you need to check one more detail regarding a limit on power to the fans. On a MOBO each standard fan header can supply power at up to 12 VDC to a maximum of 1.0 A current for all fans connected to that header. You would have to verify with the card maker what the limit is for the header on their video card - it might be the same 1.0 A max, but not guaranteed without confirmation. THEN you need the specs for the rad fans of your AIO system, probably from their maker. IF that all says those fans CAN be powered and controlled from the video card header, you're all set to make the custom connections. HOWEVER, if the total rad fan load exceeds the ability of the video card to supply power, you might need to adapt a fan HUB unit to get adequate power from elsewhere.

IF you can get all those details settled so that you CAN power and control the AIO system rad fans from a video card header, you have your solution. The AIO system PUMP matter is easier - PROBABLY (to be confirmed) it requires a simple fixed 12 VDC power source directly from a PSU output OR from a mobo case fan header that is NOT used for other fans and can be set to send out only that fixed power signal.

If that cannot be done and you want to try to access the GPU internal temperture signal to feed to some system that does ALL the GPU cooling control, that is MUCH more difficult. Just getting the signal is hard. Getting a software CONTROLLER and finding the right settings for that is even harder! In that case, your much better path is NOT to try for "Automatic Control" of GPU chip cooling. Just set it up for max cooling, or MAYBE include a way for YOU to set a fixed rad fan speed that you decide (from experience) can keep your video card properly cooled under all normal conditions.