Originally Posted by jlhawn
now i am confused, I have 2 of these fans that will be hear friday, i am going to plug each fan into it's own 3pin mother board fan header that i controll my 2 current fans with asus fan xpert. are the 2 Noctuas going to work for me in a 3pin fan header??
They work just fine; but Noctua PWM fans come with a 3 pin adapter for the LNA / ULNA. The fan itself has a 4th pin for the PWM function but 3 other pins like a standard fan.
3 Pin transmits:
The 4th pin missing from the LNA / ULNA adapters is the PWM wire that transmits the PWM signal to the fan.
It'll work just fine with the LNA / ULNA on a 3pin or 4pin header from the board; but the fan is not receiving the PWM duty cycle signal, and instead the board is pulsing 12v to the fan to reduce the fan speed based on the frequency of the pulses.