Analysis of Topology-Dependent MPI Performance on Gemini Networks

TitleAnalysis of Topology-Dependent MPI Performance on Gemini Networks
Publication TypeConference Paper
Year of Publication2013
AuthorsPena, AJ, Carvalho, RGCorrea, Dinan, J, Balaji, P, Thakur, R, Gropp, WD
Conference NameEuroMPI 2013
Conference LocationMadrid, Spain
Other NumbersANL/MCS-P4075-0513

Current HPC systems utilize a variety of interconnection networks, with varying features and communication characteristics. MPI normalizes these interconnects with a common interface used by most HPC applications. However, network properties can have a significant impact on application performance. We explore the impact of the interconnect on application performance on the Blue Waters supercomputer. Blue Waters uses a three-dimensional, Cray Geminitorus network, which provides twice the Y-dimension bandwidth in the X and Z dimensions. Through several benchmarks, including a halo-exchange example, we demonstrate that application-level mapping to the network topology yields significant performance improvements.