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 $\sim 10^9{M}_{\odot }$ 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.

我们介绍了具有MPI-OpenMP-CUDA混合并行化和接近理想的横向扩展到多个计算节点的StePS（立体投影宇宙论模拟）算法的多GPU实现。我们的新的放大宇宙学直接N体模拟方法可在给定的内存量下以前所未有的动态范围模拟无限宇宙，并且与传统的周期性模拟相反，它的基本几何形状和拓扑匹配观察结果。通过使用球面几何形状而不是周期性边界条件，并随着半径逐渐减小质量分辨率，我们的代码能够运行直径为几千兆帕，质量分辨率为$〜\mathrm{1个}{0}^9{\mathrm{中号}}_{\odot }$在三天的时间里，在中心的三个计算节点上各有四个GTX 1080 Ti GPU。该代码还可用于以合理的分辨率运行极快的模拟，以适应宇宙学参数。这些模拟对于大型调查的预测需求很有用。该步骤代码是公开的研究界。