English

4.45 Pflops Astrophysical N-Body Simulation on K computer -- The Gravitational Trillion-Body Problem

Cosmology and Nongalactic Astrophysics 2015-04-14 v5 Instrumentation and Methods for Astrophysics Computational Physics

Abstract

As an entry for the 2012 Gordon-Bell performance prize, we report performance results of astrophysical N-body simulations of one trillion particles performed on the full system of K computer. This is the first gravitational trillion-body simulation in the world. We describe the scientific motivation, the numerical algorithm, the parallelization strategy, and the performance analysis. Unlike many previous Gordon-Bell prize winners that used the tree algorithm for astrophysical N-body simulations, we used the hybrid TreePM method, for similar level of accuracy in which the short-range force is calculated by the tree algorithm, and the long-range force is solved by the particle-mesh algorithm. We developed a highly-tuned gravity kernel for short-range forces, and a novel communication algorithm for long-range forces. The average performance on 24576 and 82944 nodes of K computer are 1.53 and 4.45 Pflops, which correspond to 49% and 42% of the peak speed.

Keywords

Cite

@article{arxiv.1211.4406,
  title  = {4.45 Pflops Astrophysical N-Body Simulation on K computer -- The Gravitational Trillion-Body Problem},
  author = {Tomoaki Ishiyama and Keigo Nitadori and Junichiro Makino},
  journal= {arXiv preprint arXiv:1211.4406},
  year   = {2015}
}

Comments

10 pages, 6 figures, Proceedings of Supercomputing 2012 (http://sc12.supercomputing.org/), Gordon Bell Prize Winner. Additional information is http://www.ccs.tsukuba.ac.jp/CCS/eng/gbp2012