CPU power management based on utilization with lowest performance mode at the mid-utilization range

摘要

A demand-based method and system of central processing unit power management. The utilization of a central processing unit (CPU) during a sampling time interval is determined by measuring a time quantum within the sampling time interval during which a central processing unit clock signal is active within a processor core of the CPU. The total number of cycles of the central processing unit clock signal that are applied to the processor core and the period of the central processing unit clock signal are used to determine the time quantum. The utilization may then be expressed in terms of a ratio of the time quantum to the total time interval and used to select a processor performance mode. The CPU is then operated in the selected processor performance mode.