Extended investigation of performance-energy trade-offs under power capping in HPC environments

In the paper we present investigation of performance-energy trade-offs under power capping using modern processors. The results are presented for systems targeted at both server and client markets and were collected from Intel Xeon E5 and Intel Xeon Phi server processors as well as from desktop and mobile Intel Core i7 processors. The results, when using power capping, show that we can find various interesting combinations of energy savings and performance drops as well as non-trivial minima of the energy-execution time product. We performed this analysis for a subset of NAS Parallel Benchmark applications: BT, CG, EP and FT and sizes of the computational problem (classes A, B, C, D). We can observe that the energy characteristics visualized by a prototype of our new tool EnergyProfiler do not depend on the size of a computational problem. Consequently, the proposed tool can potentially support quick energy/performance trade-off estimation for codes similar to the tested, well-recognized benchmarks.