Performances

The results presented above were obtained on different architectures, preventing the direct comparison of the performance of the codes. However, the TauBench pseudo-benchmark~\cite{TauBench,TauBench2} made it possible to assess in a separate test the raw performance of each machine. The following sections will describe the configuration of the three high performance computing (HPC) systems that were used to run YALES2, DINO and Nek5000 for the TGV benchmarks. Subsequently, the TauBench methodology and its results on the target computers will be presented. Finally, the performance analysis for the 3-D TGV cases is discussed in the last subsection.

Presentation of the machines used for the benchmark

Irene Joliot-Curie from TGCC

The YALES2 results were obtained on the Irene Joliot-Curie machine~\cite{irene} operated by TGCC/CEA for GENCI (French National Agency for Supercomputing). %This machine built by Atos was introduced in Sept. 2018 and is ranked at the 61th position of June 2020 Top500 ranking~\cite{ireneTop500}. It is composed of 1,656 compute nodes, with 192 GB memory on each node and two sockets of Intel Skylake (Xeon Platinum 8168) with 24 cores each, operating at 2.7 GHz. Each core can deliver a theoretical peak performance of 86.4 GFlop/s with AVX-512 and FMA activated. The interconnect is an Infiniband EDR, and the theoretical maximum bandwidth is 128 GB/s per socket and thus 5.33 GB/s by core when all cores are active. The software stack consists of the Intel Compiler 19 and OpenMPI 2.0.4, both used for all results obtained in this benchmark.