Accelerating MPI Collectives with FPGAs in the Network and Novel Communicator Support

MPI collective operations can often be performance killers in HPC applications; we seek to solve this bottleneck by offloading them to reconfigurable hardware within the switch itself, rather than, e.g., the NIC. We have designed a hardware accelerator MPI-FPGA to implement six MPI collectives in the network. Preliminary results show that MPI-FPGA achieves $10 \times $ speedup in the most likely scenarios over conventional clusters. We introduce a novel mechanism that enables the hardware to support a large number of communicators of arbitrary shape, and that is scalable to very large systems. MPI-FPGA is fully integrated into MPICH and so transparent to MPI applications.