Patent ID: 8205103

Claim:
A power-source control system comprising: at least one information processing apparatus; a required-power calculation apparatus which calculates a required power representing electric power to be supplied to the information processing apparatus; a power-source apparatus which supplies the electric power calculated by the required-power calculation apparatus to the information processing apparatus; and a power-source controller which controls the power-source apparatus, wherein the information processing apparatus includes: a CPU configured to operate in accordance with each of various operating frequencies, a load measurement unit configured to measure a load of the CPU, a frequency controller configured to determine an operating frequency to be assigned to the CPU from among the various operating frequencies so that when a heavy load is applied to the CPU, a high operating frequency is attained and when a light load is applied to the CPU, a low operating frequency is attained, a load determination unit configured to generate frequency information representing the operating frequency to be determined by the frequency controller in accordance with the load of the CPU, and to transmit the generated frequency information to the required-power calculation apparatus, and the required-power calculation apparatus calculates the required power representing the electric power required for the information processing apparatus so that the CPU operates at the operating frequency represented by the frequency information received from the load determination unit, the power-source controller controls the power-source apparatus so that a highest efficiency of power conversion is attained in the power-source apparatus when the power-source apparatus supplies the required power calculated by the required-power calculation apparatus to the information processing apparatus, the power-supply apparatus adjusts electric power to be used in the information processing apparatus by supplying electric power corresponding to the required power calculated by the required power calculation apparatus to the information processing apparatus, and the frequency controller changes the operating frequency of the CPU by assigning the operating frequency represented by the frequency information to the CPU after the electric power to be used in the information processing apparatus is adjusted using the required power calculated by the required-power calculation unit.