A control system includes multiple device controllers and a device root. Each of the multiple device controllers corresponds to at least one processing unit, and is arranged to receive a hint from an application processor (AP), and generate a control signal for managing the at least one processing unit according to the hint. The device root is coupled to the multiple device controllers and includes a manager, wherein the manager is arranged to manage multiple processing units corresponding to the multiple device controllers according to multiple control signals corresponding to the multiple device controllers.