StePS: A multi-GPU cosmological N-body Code for compactified simulations

G. Rácz, I. Szapudi, L. Dobos, I. Csabai, A. S. Szalay

Research output: Contribution to journalArticle

1 Citation (Scopus)


We present the multi-GPU realization of the StePS(Stereographically Projected Cosmological Simulations) algorithm with MPI–OpenMP–CUDA hybrid parallelization and nearly ideal scale-out to multiple compute nodes. Our new zoom-in cosmological direct N-body simulation method simulates the infinite universe with unprecedented dynamic range for a given amount of memory and, in contrast to traditional periodic simulations, its fundamental geometry and topology match observations. By using a spherical geometry instead of periodic boundary conditions, and gradually decreasing the mass resolution with radius, our code is capable of running simulations with a few gigaparsecs in diameter and with a mass resolution of ∼109M in the center in four days on three compute nodes with four GTX 1080 Ti GPUs in each. The code can also be used to run extremely fast simulations with reasonable resolution for fitting cosmological parameters. These simulations are useful for prediction needs of large surveys. The StePScode is publicly available for the research community.

Original languageEnglish
Article number100303
JournalAstronomy and Computing
Publication statusPublished - Jul 2019


  • Dark matter
  • Graphics processors
  • Large-scale structure of universe
  • Methods: N-body simulations
  • Methods: Numerical

ASJC Scopus subject areas

  • Astronomy and Astrophysics
  • Computer Science Applications
  • Space and Planetary Science

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