Towards Exascale Computing for Astrophysical Simulation Leveraging the Leonardo EuroHPC System

TL;DR

This paper discusses optimizing astrophysical simulation codes for exascale computing on the Leonardo system, demonstrating efficient scalability of three flagship codes up to 1,024 GPUs.

Contribution

It presents a strategy and initial results for optimizing and scaling astrophysical codes on the Leonardo exascale system, a novel effort in this domain.

Findings

All three codes scale efficiently up to 80% at 1,024 GPUs.

Profiling tools helped identify performance bottlenecks.

Initial results demonstrate promising exascale readiness.

Abstract

Developing and redesigning astrophysical, cosmological, and space plasma numerical codes for existing and next-generation accelerators is critical for enabling large-scale simulations. To address these challenges, the SPACE Center of Excellence (SPACE-CoE) fosters collaboration between scientists, code developers, and high-performance computing experts to optimize applications for the exascale era. This paper presents our strategy and initial results on the Leonardo system at CINECA for three flagship codes, namely gPLUTO, OpenGadget3 and iPIC3D, using profiling tools to analyze performance on single and multiple nodes. Preliminary tests show all three codes scale efficiently, reaching 80% scalability up to 1,024 GPUs.