Synchronization-driven dynamic speed scaling for MPSoCs

Equalizing the ratios between workloads and speeds of processing elements provides the optimal speed allocation. Based on that principle, this work describes a dynamic speed setting policy for multiprocessor systems-on-chip (MPSoCs) that relies on the estimation of processor idle times specifically due to the synchronization work. The policy provides two advantages: first, it does not rely on any assumption about the communication pattern of the application executed by the system. Second, it is purely architectural; it automatically detects changes in the system workload and sets processors speeds accordingly by means of a custom hardware block.Results on a parallel MPEG video decoding application show an EDP saving above 55%, averaged over several datasets, corresponding to an energy saving above 50%, and a corresponding penalty in performance below 8%.