ENERGY MANAGEMENT IN GRAPHICS PROCESSING UNITS

A graphics processing unit is operable to execute graphics processing programs comprising sequences of instructions to perform graphics processing operations. The graphics processing unit includes execution processing circuitry operable to execute instructions to perform graphics processing operations and instruction issuing circuitry operable to issue instructions to be executed to the execution processing circuitry. The graphics processing unit also includes energy management circuitry operable to monitor the energy usage by the execution processing circuitry when executing instructions, determine, based on the monitoring of the energy usage, a permitted energy usage range for the execution processing circuitry when executing instructions for a future time period, and control the issuing of instructions to the execution processing circuitry by the instruction issuing circuitry during the future time period based on the permitted energy usage range determined for the future time period.