Bringing minimal routing back to HPC through silicon photonics: a study of "flexfly" architectures with the structural simulation toolkit (SST)

In system-level interconnects for high-performance computing (HPC), low-diameter hierarchical topologies like dragonfly are gaining in popularity. The topologies require adaptive routing schemes for high performance, but using non-minimal paths can stress the long-distance inter-group links that are the most expensive and scarce network resource.Âă We introduce \"FlexflyâĂIJ, a network design incorporating optical switches that steers bandwidth onto minimal paths instead of diverting packets, alleviating contention. Performance results and the simulation methodology using the Structural Simulation Toolkit (SST) are introduced.