NBSymple, a double parallel, symplectic N-body code running on Graphic Processing Units

TL;DR

NBSymple is a GPU-accelerated, symplectic N-body simulation code that achieves high speed and precision for gravitational interactions, utilizing double and single precision computations with parallelization on GPUs and CPUs.

Contribution

The paper introduces NBSymple, a novel parallelized symplectic N-body code optimized for GPUs and CPUs, balancing speed and precision for gravitational simulations.

Findings

High computational speed on NVIDIA TESLA C 1060 GPUs.

Effective use of single and double precision for accuracy and performance.

Parallelization with CUDA and OpenMP enhances scalability.

Abstract

We present and discuss the characteristics and performances, both in term of computational speed and precision, of a numerical code which numerically integrates the equation of motions of N 'particles' interacting via Newtonian gravitation and move in an external galactic smooth field. The force evaluation on every particle is done by mean of direct summation of the contribution of all the other system's particle, avoiding truncation error. The time integration is done with second-order and sixth-order symplectic schemes. The code, NBSymple, has been parallelized twice, by mean of the Computer Unified Device Architecture to make the all-pair force evaluation as fast as possible on high-performance Graphic Processing Units NVIDIA TESLA C 1060, while the O(N) computations are distributed on various CPUs by mean of OpenMP Application Program. The code works both in single precision floating point arithmetics or in double precision. The use of single precision allows the use at best of the GPU performances but, of course, limits the precision of simulation in some critical situations. We find a good compromise in using a software reconstruction of double precision for those variables that are most critical for the overall precision of the code. The code is available on the web site astrowww.phys.uniroma1.it/dolcetta/nbsymple.html