Authors: Ataru Tanikawa, Kohji Yoshikawa, Takashi Okamoto, Keigo Nitadori
Date: 14 Apr 2011
Abstract: We present a high-performance N-body code for astronomical collisional systems accelerated with the aid of a new SIMD instruction set extension of the x86 architecture: Advanced Vector eXtensions (AVX), an enhanced version of the Streaming SIMD Extensions (SSE). With one processor core of Intel Core i7-2600 processor (8MB cache and 3.40 GHz) based on Sandy Bridge micro-architecture, we achieved the performance of ~ 20 giga floating point number operations per second (GFlops) for double-precision accuracy, which is two times and five times higher than that of the previously developed code implemented with the SSE instructions (Nitadori et al., 2006b), and that of a code implemented without any explicit use of SIMD instructions with the same processor core. We have parallelized the collisional N-body code by using so-called NINJA scheme (Nitadori et al., 2006a), and achieved ~ 90 GFlops for a system containing more than N = 8192 particles with 8 MPI processes on four cores. We can expect to achieve about 10 tera Flops (TFlops) for an astronomical collisional system with N ~ 10ˆ5 on massively parallel systems with at most 800 cores with Sandy Bridge micro-architecture. This performance will be comparable to that of Graphic Processing Unit (GPU) cluster systems. This paper offers an alternative to collisional N-body simulations with GRAPEs and GPUs.
© M. Vallisneri 2012 — last modified on 2010/01/29
Tantum in modicis, quantum in maximis