Abit FP-IN9 & Noctua NF-B9 PWM

[svkap]

Hi guys, I replaced recently my old 3 pin cpu fan Noctua NF-B9 with the new 4 pin PWM version.
In bios if CPU FanEQ Control is set to disabled, at PC startup or CPU on idle, PWM fan runs at full speed, over 1700 rpm.
If CPU FanEQ Control is set to enabled I can set ratios.

The old fan NF-B9 NO PWM was connected to System 3 pin fan connector, SYS FanEQ Rederence Temp. was set on "CPU".
If SYS FanEQ Control is set to enabled I can set ratios, if not, fan runs at full speed, exactly as the PWM version.

The strange thing is that PWM works exactly as NO PWM version, if CPU FanEQ Control is set to disabled, at PC startup or CPU on idle, PWM fan should NOT run at full speed!

[Bambooz]

if CPU FanEQ Control is set to disabled, at PC startup or CPU on idle, PWM fan should NOT run at full speed!

Yes it should. If the FanEQ is disabled, the fan gets full 12V and no PWM signal to adjust the speed (or in case of a 3pin fan, the voltage is at 12V all the time and doesn't get regulated down to adjust the fan speed)

Disabling FanEQ makes the fans act like as if they were directly connected to 12V, i.e. they run at full speed (unregulated) all the time, no matter if it's 3pin or PWM. It's normal that way.

[svkap]

If I remember well, Intel stock pwm cpu fan works correctly even with FanEQ Control disabled.