Porting ATLAS Fast Calorimeter Simulation to GPUs with Performance Portable Programming Models

• Published in: EPJ Web of conferences Vol. 295; p. 11018
• Main Authors: Atif, Mohammad, Dong, Zhihua, Leggett, Charles, Lin, Meifeng, Tsulaia, Vakhtang
• Format: Journal Article Conference Proceeding
• Language: English
• Published: Les Ulis EDP Sciences 01.01.2024
• Subjects: Data transfer (computers); Energy distribution; Floating point arithmetic; Graphics processing units; MATHEMATICS AND COMPUTING; Particle energy; Performance evaluation
• ISSN: 2100-014X; 2101-6275; 2100-014X
• DOI: 10.1051/epjconf/202429511018

FastCaloSim is a parameterized simulation of the particle energy response and of the energy distribution in the ATLAS calorimeter. It is a relatively small and self-contained package with massive inherent parallelism and captures the essence of GPU offloading via important operations like data transfer, memory initialization, floating point operations, and reduction. It was identified by the High Energy Physics Center for Computational Excellence project as a good testbed for evaluating the performance and ease of portability of programming models. In this paper, we will discuss the results of our evaluation of the porting process to Kokkos, SYCL, Alpaka, OpenMP and std::par (nvc++), and compare performance on NVIDIA, AMD and Intel GPUs, as well as multicore CPUs.