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Fan Setup

Discussion in 'General Hardware' started by Rowan88, 15 Sep 2021.

  1. Rowan88

    Wise Guy

    Joined: 2 Jun 2013

    Posts: 1,224

    Location: Glasgow

    Hi.

    My nephew bought a 3 pack of cheap fans. On each one it had a molex and 3 pin header.

    Am I correct in saying if you connect via molex the fans will run at full speed constantly?

    If I ignore the molex and just connect them via 3 pin header to ports on the motherboard (Tomahawk B450 II) then I should change the BIOS to Smart Fan then PWM then it will run quiet and ramp up based on temps?

    Cheers
     
  2. Dg834man

    Gangster

    Joined: 2 Sep 2016

    Posts: 329

    you got a link to these fans, pretty weird having molex and 3 pin for power, these days if a fan has two separate cables one is for power the other for rgb.

    Yeah if they are connected to molex they will just run at a set speed.

    3 pin fans aren't pwm the 4 pin ones are but you can still control them via bios in voltage mode
     
  3. Rowan88

    Wise Guy

    Joined: 2 Jun 2013

    Posts: 1,224

    Location: Glasgow

    They were on the "website that using prime". Think the brand was upHere.

    Im not a fan (pun intended) of them but I swapped them over to using onboard 3 pin headers then in the BIOS changed it to DC and enabled Smart Fan.

    I was told PWM wouldn't work as the 4th pin is missing so DC will do a similar thing by sending "bursts" of voltage to the fans depending on temp.

    Cheers