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May 8 – 12, 2023
Norfolk Waterside Marriott
US/Eastern timezone

Porting ATLAS FastCaloSim to GPUs with Performance Portable Programming Models

May 9, 2023, 3:00 PM
Marriott Ballroom VII (Norfolk Waterside Marriott)

Marriott Ballroom VII

Norfolk Waterside Marriott

235 East Main Street Norfolk, VA 23510


Leggett, Charles (Lawrence Berkeley National Laboratory)


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. Thus, it was identified as a good testbed for evaluating the performance and ease
of portability of programming models. As a part of the HEP Center for Computational Excellence project, FastCaloSim had been ported to GPU using CUDA, Kokkos, SYCL, and similar ports for std::parallel, Alpaka, and OpenMP are being developed.

In this presentation, we will give an overview of the progress made with the std::parallel, Alpaka and OpenMP implementations of FastCaloSim. In particular, performance benchmarks on NVIDIA
GPUs, AMD GPUs and multicore CPUs will be reported for each programming model wherever available, along with the comparison of pros and cons of each approach.

Consider for long presentation No

Primary authors

Atif, Mohammad (Brookhaven National Laboratory) Dong, Zhihua (Brookhaven National Laboratory) Leggett, Charles (Lawrence Berkeley National Laboratory) Lin, Meifeng (Brookhaven National Laboratory) Tsulaia, Vakho (LBNL)

Presentation materials

Peer reviewing