Thank you both! On the Mobo, when I have changed the CPU_fan header from DC to PWM, the pump started to run at full. The AIO has its own controller box which one must use, as the connection from the pump and from the fans are proprietary ones. Some say, the best is to have the pump run at full speed, or almost full speed at all times. If I understood correctly, since the pump’s connection is 3 pins, DC or PWM makes no difference in a sense, as DC would control speed by varying voltage, whereas PWM is constant 12V and the speed signal would be via pin4 which is not available in this case. Did I get it correctly?