1. A computing system comprising: one or more multicore processors, wherein each multicore processor comprises a set of one or more processing units, wherein each processing unit is operable at a variable frequency; a main memory, wherein the main memory is operable at a variable frequency; and a feedback controller, wherein the feedback controller configured to control the variable frequency of a processing unit; and the variable frequency of the main memory is dependent on a measurement, the measurement is representative of a current performance of an application running on one or more of the processing units of the set.