I have grasped that fans with 3 pin plugs are considered to be DC fans and as such would normally be controlled by voltage. My new case has 4 RGB fans, with 3 pin plugs and I have a PHANTEKS UNIVERSAL FAN CONTROLLER. On my MAG B550 Tomahawk MB I can only see one PWM header and it is marked up as 'PUMP_FAN 1' My system is not fitted with AIO cooling, so as this header is currently not used, is it permissible to connect my fan hub to this header, to enable PWM control of my 3 pin fans? By omitting the SATA power connection to the power supply, the maximum load capacity of the PWM hub is limited to a total of 30 Watts!' It installations instructions goes on to say that if a PWM Header is not used to feed the Fan hub: - ' Note: If the 4-Pin PWM cable of the hub is not connected to a PWM connector on the motherboard, but instead to a 4-Pin- or 3-Pin port that is voltage regulated, the additional SATA power connector cannot be used, or all fans will spin at full speed. However, reading the Fan Hub instructions it seems to suggest that these 3 pin fans can be controlled under PWM, when connected to the hub, providing the hub picks up its signal from a PWM header and the hub can then powered by a SATA feed.

Pwm fan motherboard