Exascale Interconnect Topology Characterization and Parameter Exploration

Exascale promotes numerous new challenges in supercomputer designs; Interconnect topology is one of them. Emerging interconnect topologies have been proposed but have not been thoroughly studied at large scale. In this study, we use a cycle-accurate simulator to conduct a design space exploration for both new and traditional interconnect topologies at the scale of 50,000 and 100,000 node networks. For each topology, we evaluate the performance with various network parameters (link latency and bandwidth), routing algorithms and multiple prevalent MPI workloads. Using these, we are able to characterize these topologies with regards to workloads, network parameters, and scalability to provide insights on the network system design for future Exascale systems.