2006/08/04 by Stefan Harfst, Alessia Gualandris, David Merritt +3 · 172 citations
Engineering · Physics and Astronomy · #Algorithm #Computation #Computational science #Computer science #InfiniBand #Operating system #Overhead (engineering) #Parallel computing #Physics #Quantum mechanics #Radio Astronomy Observations and Technology #Satellite Communication Systems #Superconducting and THz Device Technology #astro-ph #n-body problem
paper · pdf · doi:10.1016/j.newast.2006.11.003
published in New Astronomy 12(5), 357-377 (Elsevier BV) · 34 pages, 15 figures, submitted to New Astronomy
arxiv created 2006/08/04 · openalex publication_date 2006/12/13 · arxiv updated 2009/12/01 · openalex created_date 2025/10/10 · openalex updated_date 2026/08/06
Direct-summation N-body algorithms compute the gravitational interaction between stars in an exact way and have a computational complexity of O(N2). Performance can be greatly enhanced via the use of special-purpose accelerator boards like the GRAPE-6A. However the memory of the GRAPE boards is limited. Here, we present a performance analysis of direct N-body codes on two parallel supercomputers that incorporate special-purpose boards, allowing as many as four million particles to be integrated. Both computers employ high-speed, Infiniband interconnects to minimize communication overhead, which can otherwise become significant due to the small number of "active" particles at each time step. We find that the computation time scales well with processor number; for 2*106 particles, efficiencies greater than 50% and speeds in excess of 2 TFlops are reached.