Question Can't Set CPU Fan Duty Cycle Below 60%

[steve489]

I've just built a new PC using an Asus TUF Gaming Plus WiFi Z790 board and a Noctua NH-D14 cooler. The Noctua cooler has a Noctua NF-P12 PWM fan and a Noctua NF-P14 PWM fan connected via a splitter cable to the CPU fan header. All works fine but in the BIOS I can't set a CPU fan duty cycle below 60% for the fan curve whereas I can for the other fans.

Why is this - perhaps something to do with connecting the fans via a splitter cable?

 

[kerberos_20]

use low noise adaptor which came with that cooler

 

[Paperdoc]

Personally I don't like to use the Low Noise Adapter with fans operated by an automatic control system. The adapter merely drops the Voltage supplied and limits the control process.

Do you have the Profile selection at the bottom of the QFan Control screen set to Manual? You need to do that if you want to set your own custom fan curve. Otherwise if you set to Standard it will use its default fan curve which I expect WILL run the CPU cooler lower than 60% when it is cold after a start-up.

 

[steve489]

Personally I don't like to use the Low Noise Adapter with fans operated by an automatic control system. The adapter merely drops the Voltage supplied and limits the control process.

Do you have the Profile selection at the bottom of the QFan Control screen set to Manual? You need to do that if you want to set your own custom fan curve. Otherwise if you set to Standard it will use its default fan curve which I expect WILL run the CPU cooler lower than 60% when it is cold after a start-up.

I've now connected the two Noctua CPU fans to separate connectors (CPU_FAN & CPU_OPT). I still can't set a fan duty cycle below 60% in QFan in manual mode. I'm not sure if this is by design or a bug.

 

[Zerk2012]

I've now connected the two Noctua CPU fans to separate connectors (CPU_FAN & CPU_OPT). I still can't set a fan duty cycle below 60% in QFan in manual mode. I'm not sure if this is by design or a bug.

You should leave the CPU fan curve alone.

 

[steve489]

Update - I've now use =d the QFan training option which now lets me set a minimum CPU fan duty cycle of 50% rather than 60%