Patent ID: 8219839

Claim:
In a power distribution system in which a plurality of information processing apparatuses, undergoing fluctuations of power consumption and performance owing to a power mode being set, is connected to a management module, for allocating power to the plurality of information processing apparatuses, via a network, said power distribution system characterized in that when the information processing apparatus needs surplus power allocation, the information processing apparatus sends a power allocation request to the management module so that the management module sends back a power allocation response to the information processing apparatus via a communication line, wherein the management module includes a first control calculation unit and a first storage unit, wherein the first storage unit stores an allocated power management table, which describes an upper-limit value of power entirely allocated to the plurality of information processing apparatuses and an allocated power allocated to each information processing apparatus, and a power pool unallocated to any one of the information processing apparatuses, wherein the information processing apparatus includes a power sensor measuring real power consumption, a second control calculation unit, and a second storage unit, wherein the second storage unit stores the power mode, a power mode management table describing a maximum power value for each power mode and an upper mode request threshold for requesting transition to an upper power mode, the allocated power, and redundant power, wherein the second control calculation unit calculates the redundant power based on a difference between the allocated power and the real power consumption, thus updating the redundant power stored in the second storage unit, wherein the first control calculation unit collects the redundant power and adds it to the power pool, wherein when the information processing apparatus requests additional power allocation, the first control calculation unit allocates a part of or the entirety of the power pool to the information processing apparatus, wherein the second control calculation unit changes the power mode in response to the allocated power, wherein the first storage unit stores a pool threshold representing a lower-limit value of the power pool, and wherein the first control calculation unit collects the redundant power only when the power pool is below or equal to the pool threshold.