Study on Real Effect of Non-Blocking Collective Communications on JHPCN Supercomputers

NBC (Non-Blocking Collective Communications) is expected to be a tool to hide communication overhead by overlapping computation. However, the use of NBC is currently limited to a small number of applications. To encourage the programmers to modify their programs to overlap communication and computation with NBC, we are studying their real effects on supercomputers as a JHPCN project. This talk reports on the current state of our study.