The Performance and Scalability of the SHMEM and Corresponding MPI-3 Routines on a Cray XC30

In this paper the authors compare the performance and scalability of the SHMEM and corresponding MPI-3 routines for five different benchmark tests using a Cray XC30. The performance of the MPI-3 get and put operations was evaluated using fence synchronization and also using lock-unlock synchronization. The five tests used communication patterns ranging from light to heavy data traffic: accessing distant messages, circular right shift, gather, broadcast and all-to-all. Each implementation was run using message sizes of 8 bytes, 10 Kbytes and 1 Mbyte and up to 768 processes. For nearly all tests, the SHMEM get and put implementations outperformed the MPI-3 get and put implementations. The authors noticed significant performance increase using MPI-3 instead of MPI-2 when compared with performance results from previous studies.