Patent ID: 8473765

Claim:
A method for adjusting central processing unit (CPU) frequency according to a CPU utilization rate in a computer, the method comprises the following steps: turning on the computer to boot a Basic Input Output System (BIOS); starting a performance monitor in the CPU by the BIOS; turning on a timer by the BIOS; reading a system management interrupt program during a time period by the timer; recording a number of clock signals and time values by the performance monitor in two adjacent time periods; determining the CPU utilization rate by the performance monitor according to the number of clock signals, the time values, and a CPU clock speed; wherein the CPU utilization rate is calculated according to: C ⁢ ⁢ 2 - C ⁢ ⁢ 1 ( T ⁢ ⁢ 2 - T ⁢ ⁢ 1 ) × f ; wherein C 1 and C 2 are number of clocked signals in the two adjacent time periods; T 1 and T 2 are the time values in the two adjacent time periods; and f is the CPU clock speed; adjusting a CPU frequency by the BIOS according to the CPU utilization rate; and booting the computer's operation system (OS) by the BIOS.