Per the title, I have installed some high cfm and high wattage fans on my 4080, it works fine but i’m currently using a manual knob to control the dc. Because I bought them without even a fan header, they just have 2pin connectors - does anyone know of any controller hubs I can use to both power them (.7a/8.4w per fan), and control the dc via a mobo header?
Nope. Too much power for consumer fan controllers. Most of them barely use 2W per fan.
Well, you can get an Arduino and code your own hub, you’re already able to control it with a knob, so just automate it with a microcontroller.
And a mosfet between Arduino and the fan. Arduino generally tops out at 20mA per pin which is 0.1w. A decent mosfet can handle several amps and can even drive 12v fan from a 5v pin.
/r/AskElectronics should be a good place to ask for the right kind of mosfet that is able to handle 1A or more (want to have some margin), can be driven by 5v at gate pin and can handle 12v at source and drain pin.