GAMER: a GPU-Accelerated Adaptive Mesh Refinement Code for Astrophysics

TL;DR

GAMER is a GPU-accelerated adaptive mesh refinement code that significantly speeds up astrophysical simulations by leveraging GPU parallelism, achieving over 10x speed-up in large-scale cosmological models.

Contribution

The paper introduces GAMER, a novel GPU-based AMR astrophysics simulation code with optimized data transfer and parallel processing capabilities, enabling large-scale, high-resolution simulations.

Findings

Achieves over 12x speed-up with 1 GPU for high-resolution simulations.

Demonstrates accurate results through standard astrophysics tests.

Supports multi-GPU parallelism for large-scale cosmological simulations.

Abstract

We present the newly developed code, GAMER (GPU-accelerated Adaptive MEsh Refinement code), which has adopted a novel approach to improve the performance of adaptive mesh refinement (AMR) astrophysical simulations by a large factor with the use of the graphic processing unit (GPU). The AMR implementation is based on a hierarchy of grid patches with an oct-tree data structure. We adopt a three-dimensional relaxing TVD scheme for the hydrodynamic solver, and a multi-level relaxation scheme for the Poisson solver. Both solvers have been implemented in GPU, by which hundreds of patches can be advanced in parallel. The computational overhead associated with the data transfer between CPU and GPU is carefully reduced by utilizing the capability of asynchronous memory copies in GPU, and the computing time of the ghost-zone values for each patch is made to diminish by overlapping it with the GPU computations. We demonstrate the accuracy of the code by performing several standard test problems in astrophysics. GAMER is a parallel code that can be run in a multi-GPU cluster system. We measure the performance of the code by performing purely-baryonic cosmological simulations in different hardware implementations, in which detailed timing analyses provide comparison between the computations with and without GPU(s) acceleration. Maximum speed-up factors of 12.19 and 10.47 are demonstrated using 1 GPU with 4096^3 effective resolution and 16 GPUs with 8192^3 effective resolution, respectively.