Strong Scaling of OpenACC enabled Nek5000 on several GPU based HPC systems

Vincent J, Gong J, Karp M, Peplinski A, Jansson N, Podobas A, Jocksch A, Yao J, Hussain F, Markidis S, Karlsson M, Pleiter D, Laure E, Schlatter P (2022)


Publication Type: Conference contribution

Publication year: 2022

Publisher: Association for Computing Machinery

Pages Range: 94-102

Conference Proceedings Title: ACM International Conference Proceeding Series

Event location: Virtual, Online, JPN

ISBN: 9781450384988

DOI: 10.1145/3492805.3492818

Abstract

We present new results on the strong parallel scaling for the OpenACC-accelerated implementation of the high-order spectral element fluid dynamics solver Nek5000. The test case considered consists of a direct numerical simulation of fully-developed turbulent flow in a straight pipe, at two different Reynolds numbers Reτ = 360 and Reτ = 550, based on friction velocity and pipe radius. The strong scaling is tested on several GPU-enabled HPC systems, including the Swiss Piz Daint system, TACC's Longhorn, Jülich's JUWELS Booster, and Berzelius in Sweden. The performance results show that speed-up between 3-5 can be achieved using the GPU accelerated version compared with the CPU version on these different systems. The run-time for 20 timesteps reduces from 43.5 to 13.2 seconds with increasing the number of GPUs from 64 to 512 for Reτ = 550 case on JUWELS Booster system. This illustrates the GPU accelerated version the potential for high throughput. At the same time, the strong scaling limit is significantly larger for GPUs, at about 2000 - 5000 elements per rank; compared to about 50 - 100 for a CPU-rank.

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APA:

Vincent, J., Gong, J., Karp, M., Peplinski, A., Jansson, N., Podobas, A.,... Schlatter, P. (2022). Strong Scaling of OpenACC enabled Nek5000 on several GPU based HPC systems. In ACM International Conference Proceeding Series (pp. 94-102). Virtual, Online, JPN: Association for Computing Machinery.

MLA:

Vincent, Jonathan, et al. "Strong Scaling of OpenACC enabled Nek5000 on several GPU based HPC systems." Proceedings of the 5th International Conference on High Performance Computing in Asia-Pacific Region, HPC Asia 2022, Virtual, Online, JPN Association for Computing Machinery, 2022. 94-102.

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