Patent ID: 8145926

Claim:
A method comprising determining a processor within a system is operating in a low temperature state, wherein while the processor is operating in the low temperature state the processor does not require cooling and a fan within the system used to cool the processor is typically off or operating at a low speed; determining a preferred speed for the fan to operate at in order to reduce system power when the processor is operating in the low temperature state, wherein the system power includes processor power and fan power, wherein the system power is reduced when the processor power saved by cooling the processor operating in the low temperature state with the fan operating at the preferred speed outweighs the fan power required to operate the fan at the preferred speed, and wherein the determining a preferred speed for the fan includes measuring the processor power and the fan power when it is initially determined that the processor is operating in a low temperature state prior to any fan speed adjustments, calculating the system power prior to any fan speed adjustments, increasing the fan speed, measuring the processor power and the fan power for the increased fan speed, calculating the system power for the increased fan speed, dynamically adjusting the fan speed based on changes to the system power, measuring the processor power and the fan power for the dynamically adjusted fan speed, calculating the system power for the dynamically adjusted fan speed, and selecting the preferred speed when the system power is determined to be substantially at lowest value; and running the fan at the preferred speed when the processor is operating in the low temperature state.