Performance of the Supercomputer Fugaku for Breadth-First Search in Graph500 Benchmark.

In this paper, we present the performance of the supercomputer Fugaku for breadth-first search (BFS) problem in the Graph500 benchmark, which is known as a ranking benchmark used to evaluate large-scale graph processing performance on supercomputer systems. Fugaku is a huge-scale Japanese exascale supercomputer that consists of 158,976 nodes connected by the Tofu interconnect D (TofuD). We have developed a BFS implementation that can extract the performance of Fugaku. We also optimize the number of processes per node, one-to-one communication, performance power ratio, and process mapping in the six-dimensional mesh/torus topology of TofuD. We evaluate the BFS performance for a large-scale graph consisting of about 2.2 trillion vertices and 35.2 trillion edges using the whole Fugaku system, and achieve 102,956 giga-traversed edges per second (GTEPS), resulting in the first position of Graph500 BFS ranking in November 2020. This performance is 3.3 times higher than that of Fugaku’s previous system, the K computer.