Poster: Evaluating Communication Performance in BlueGene/Q and Cray XE6 Supercomputers

Evaluation of the communication performance in supercomputers Blue Gene/Q and Cray XE6 using MPI and lower level libraries are presented. MPI is widely used for to its simplicity, portability and straightforwardness, however it also introduces overhead that degrades communication performance. Some applications with performance constraints cannot tolerate that degradation. Recent supercomputers such as the Blue Gene/Q and CrayXE provide lower level communications libraries such as PAMI (Parallel Active Message Interface) and uGNI (User Generic Network Interface). Our experiments show that with different communications modes: one-sided, two-sided, inter-node, intra-node, we can achieve higher performance with certain message sizes. These results will enable us to develop a light-weight API for GLEAN which is a framework for I/O acceleration and in situ analysis, to get improved performance on these systems.