An ECM-based energy-efficiency optimization approach for bandwidth-limited streaming kernels on recent Intel Xeon processors

We investigate an approach that uses low-level analysis and the execution-cache-memory (ECM) performance model in combination with tuning of hardware parameters to lower energy requirements of memory-bound applications. The ECM model is extended appropriately to deal with software optimizations such as non-temporal stores. Using incremental steps and the ECM model, we analytically quantify the impact of various single-core optimizations and pinpoint microarchitectural improvements that are relevant to energy consumption. Using a 2D Jacobi solver as example that can serve as a blueprint for other memory-bound applications, we evaluate our approach on the four most recent Intel Xeon E5 processors (Sandy Bridge-EP, Ivy Bridge-EP, Haswell-EP, and Broadwell-EP). We find that chip energy consumption can be reduced in the range of 2.0-2.4$\times$ on the examined processors.