SpectralFly: Ramanujan Graphs as Flexible and Efficient Interconnection Networks [article]

Stephen Young, Sinan Aksoy, Jesun Firoz, Roberto Gioiosa, Tobias Hagge, Mark Kempton, Juan Escobedo, Mark Raugas
2022 arXiv   pre-print
In recent years, graph theoretic considerations have become increasingly important in the design of HPC interconnection topologies. One approach is to seek optimal or near-optimal families of graphs with respect to a particular graph theoretic property, such as diameter. In this work, we consider topologies which optimize the spectral gap. We study a novel HPC topology, SpectralFly, designed around the Ramanujan graph construction of Lubotzky, Phillips, and Sarnak (LPS). We show combinatorial
more » ... operties, such as diameter, bisection bandwidth, average path length, and resilience to link failure, of SpectralFly topologies are better than, or comparable to, similarly constrained DragonFly, SlimFly, and BundleFly topologies. Additionally, we simulate the performance of SpectralFly on a representative sample of micro-benchmarks using the Structure Simulation Toolkit Macroscale Element Library simulator and study cost-minimizing layouts, demonstrating considerable benefit of the SpectralFly topology.
arXiv:2104.11725v2 fatcat:cdavfzaepjaefpbqo2hvlzjbo4