[SOLVED] PWM to DC speed control

Solution
Your manual, page 1-17 has all info about your fan connectors.
Page 3-7 has info on setting fan profiles and selecting PWM or DC mode in BIOS.
Post back here the maker and exact model number of your mobo, so we can look up its manual and advise. Most mobos now use only 4-pin fan headers, BUT have options in BIOS Setup to let you choose to have those headers operate either as true PWM Mode headers or as older Voltage Control Mode (aka DC Mode) headers required for 3-pin fan control.
 
Post back here the maker and exact model number of your mobo, so we can look up its manual and advise. Most mobos now use only 4-pin fan headers, BUT have options in BIOS Setup to let you choose to have those headers operate either as true PWM Mode headers or as older Voltage Control Mode (aka DC Mode) headers required for 3-pin fan control.
Ho, I see, didn't know that. I've looked at the manual but didn't find such a thing.

My MOBO: Asus ROG Strix X570-F Gaming and the Manual