CUBE2: A Parallel $N$-Body Simulation Code for Scalability, Accuracy, and Memory Efficiency

TL;DR

CUBE2 is a scalable, memory-efficient, and accurate open-source N-body simulation code for cosmology, utilizing multi-level Particle-Mesh methods and optimized algorithms to handle large particle counts effectively.

Contribution

We introduce CUBE2, a novel N-body simulation code that improves scalability, memory efficiency, and precision for large-scale cosmological simulations.

Findings

Successfully simulated $6144^3$ particles on ACECS.

Achieved high computational performance and accuracy.

Enhanced memory management for large particle datasets.

Abstract

$N$-body simulation serves as a critical method for modeling cosmic evolution and poses a significant challenge in high-performance computing. We present CUBE2, an open-source cosmological $N$-body code emphasizing memory efficiency, computational performance, scalability and precision. The core of its algorithm utilizes multi-level Particle-Mesh (PM) method to solve the Poisson equation for matter distribution, leveraging the well-optimized Fast Fourier Transform (FFT) for computational efficiency. Precision is ensured by the optimized Green's function that seamlessly bridges gravitational interactions between multi-level PM and Particle-Particle (PP) calculations. The program design enhances per-core/node efficiency in processing $N$-body particles, while the Information Optimized Storage (IOS) addresses memory constraints for large particle counts. Using CUBE2, we run two cosmological simulations with particle counts of $6144^3$ on the Advanced Computing East China Sub-center (ACECS) to test performance and accuracy.