Patent ID: 8181051

Claim:
An electronic apparatus comprising: a hardware element arranged to operate in a first energy usage mode for providing a first level of performance, the hardware element having a second energy usage mode for providing a second level of performance; an energy-conservation module arranged to determine a performance level required of the hardware element based on a platform cost rule for the hardware element and a first duration for providing the performance level, wherein the platform cost rule includes a plurality of fields identifying parameters for the hardware element including a first field identifying that a power mechanism associated with the hardware element uses dynamic frequency scaling or dynamic voltage scaling; and a store comprising data associated with the hardware element transitioning between the first energy usage mode and the second energy usage mode, the data characterising power use and performance; wherein the energy conservation module is arranged to use the data to determine whether an energy saving is achievable should the hardware element transition into the second energy usage mode and use the second energy usage mode in order to satisfy the performance level required during the first duration.