MPI software stacks are complex beasts that play a key role in application performance. Guix packages Open MPI for a wide range high-speed interconnects—InfiniBand, Omni-Path, Slingshot, ROCE, you name it—with the goal of achieving peak performance for each one of them.
High-speed network interconnects are a key component of supercomputers. The challenge from a software packaging viewpoint is to provide an MPI stack able to get the performance out of that specialized networking hardware. As packagers, our approach has been to provide MPI packages that get the best performance of the underlying interconnect, be it Omni-Path, InfiniBand, or any other type of interconnect.
High-performance networks have constantly been evolving, in sometimes hard-to-decipher ways. Once upon a time, hardware vendors would pre-install an MPI implementation (often an in-house fork of one of the free MPI implementations) specially tailored for their hardware. Fortunately, this time appears to be gone. Despite that, there is still widespread belief that MPI cannot be packaged in a way that achieves best performance on a variety of contemporary high-speed networking hardware.
