Some fan power help!

Allunia · April 20, 2019

I have an AIO corsair 115i pro rgb

it comes with a sata connection for power and you also connect a usb on mobo for extra monitoring etc.

At the base of the pump it splits into 2x4pin cables for the 2 included fans.

My problem is that i have 4x140 ML fans

at push/pull but only 2 of them are. controlled by the cpu curve i have set.

I do have a 4slot hub fan splitter(with no extra power) that i can use to connect all 4 fans at one of the aio cables and leave the other unplugged.

Will i have any problems? what will happen if i overload the fan cable?

does the sata power that comes from the aio suffice for pump+ fans and leds?

how can i use all 4 fans in one slot?

edit: is it better if i split the fans at two for each cable of the aio?

alyen · April 20, 2019

I've been wondering about this as well since I have a 360 AIO on order I am considering a push and pull configuration with 2 Deep Cool fan hubs (FH-4 model). I know my motherboard can supply 1 amp for each fan hub and have been using 3 fans max that are only .08a each. I'm afraid to put 4 fans into one header for long time use even if I think it can handle it.

Not sure about that specific Corsair AIO model, but the Commander Pro hub I own seems to provide enough power from a single SATA power cable for 6 fan and 2 LED headers when its plugged into the USB header.

I'm going with Deep Cool fan hub to let the motherboard control the fans. You need 4 pin fans to have PWM with that hub from my understanding. Not sure if there are any other hubs for this sort of setup.

Blai5e · April 20, 2019

2 hours ago, Allunia said:

<snip>

Will i have any problems? what will happen if i overload the fan cable?

does the sata power that comes from the aio suffice for pump+ fans and leds?

how can i use all 4 fans in one slot?

edit: is it better if i split the fans at two for each cable of the aio?

I'm running a H115i on my test bench and use 4 x ML-140's in push-pull (not required but I had the fans) and use a 2-way PWM fan splitter on each of the CLC's fan headers - it'll handle the power. The NZXT Kraken X62 has 4 fan tails on their CLC for just such a purpose. That's the route I'd suggest if you want to run push-pull rather than introduce an extra hub to the mix. Also note the paragraph I have highlighted in bold below.

35 minutes ago, alyen said:

<snip>

Not sure about that specific Corsair AIO model, but the Commander Pro hub I own seems to provide enough power from a single SATA power cable for 6 fan and 2 LED headers when its plugged into the USB header.

I'm going with Deep Cool fan hub to let the motherboard control the fans. You need 4 pin fans to have PWM with that hub from my understanding. Not sure if there are any other hubs for this sort of setup.

The Commander Pro has enough juice to run multiple fans per header but "unofficially", only run 2 x fans max. from each header. (This was confirmed by a Corsair staffer on their forum but this isn't documented anywhere else.) I did have 3-way PWM splitters on a couple of headers for a while and the Commander Pro ended up confused and disabling one of them necessitating a factory reset of the device (having 3 hands for this activity would've been handy) to restore the header.

CLC's are designed to have their fan curves based of the liquid temperature (unless you like the sound of your fans ramping up and down as the CPU load continually varies). If you move your fans to a separate hub, you probably won't have access to the CLC's liquid temperature to base your fan curve upon.

Edit 1: If you use a Commander Pro, you will be able to access a Corsair CLC's liquid temperature to base a fan curve upon. It'll work once the USB drivers have loaded in Windows, prior to Windows loading, they'll blast at 100%.

Edit 2: If you use one of the temperature probes supplied with the Commander Pro on the exhaust side of the radiator, you will have an additional temperature source that doesn't require USB communication to access. The probe will read a slightly higher than the liquid (1~3°C) but it'll be available at all times. I use an inline temperature probe (10kΩ sensor) on my open loop and am going to add a second one next maintenance cycle as I use 2 x Commander Pro's and currently rely on USB communication to get the liquid temperature reading across to the 2nd unit.