Accurate Characterization of the Variability in Power Consumption in Modern Mobile Processors

The variability in performance and power consumption is slated to grow further with continued scaling of process technologies. While this variability has been studied and modeled before, there is lack of empirical data on its extent, as well as the factors affecting it, especially for modern general purpose microprocessors. Using detailed power measurements the authors show that the part to part variability for modern processors utilizing the Nehalem micro-architecture is indeed significant. They chose six Core i5-540M laptop processors marketed in the same frequency bins - thus presumed to be identical - and characterized their power consumption for a variety of representative single-threaded and multithreaded application workloads.