Under the hood of SYCL – an initial performance analysis with an unstructured-mesh CFD application

Research output: Chapter in Book/Report/Conference proceedingConference contribution


  • Istvan Z. Reguly
  • Andrew M.B. Owenson
  • Archie Powell
  • Stephen Jarvis
  • Gihan R. Mudalige

Colleges, School and Institutes

External organisations

  • Pazmany Peter Catholic University
  • University of Warwick


As the computing hardware landscape gets more diverse, and the complexity of hardware grows, the need for a general purpose parallel programming model capable of developing (performance) portable codes have become highly attractive. Intel’s OneAPI suite, which is based on the SYCL standard aims to fill this gap using a modern C++ API. In this paper, we use SYCL to parallelize MG-CFD, an unstructured-mesh computational fluid dynamics (CFD) code, to explore current performance of SYCL. The code is benchmarked on several modern processor systems from Intel (including CPUs and the latest Xe LP GPU), AMD, ARM and Nvidia, making use of a variety of current SYCL compilers, with a particular focus on OneAPI and how it maps to Intel’s CPU and GPU architectures. We compare performance with other parallelizations available in OP2, including SIMD, OpenMP, MPI and CUDA. The results are mixed; the performance of this class of applications, when parallelized with SYCL, highly depends on the target architecture and the compiler, but in many cases comes close to the performance of currently prevalent parallel programming models. However, it still requires different parallelization strategies or code-paths be written for different hardware to obtain the best performance.

Bibliographic note

Funding Information: Acknowledgment. This research is supported by Rolls-Royce plc., and by the UK Engineering and Physical Sciences Research Council (EPSRC): (EP/S005072/1 – Strategic Partnership in Computational Science for Advanced Simulation and Modelling of Engineering Systems – ASiMoV). Gihan Mudalige was supported by the Royal Society Industry Fellowship Scheme(INF/R1/1800 12). István Reguly was supported by National Research, Development and Innovation Fund of Hungary, project PD 124905, financed under the PD 17 funding scheme. Publisher Copyright: © 2021, Springer Nature Switzerland AG.


Original languageEnglish
Title of host publicationHigh Performance Computing
Subtitle of host publication36th International Conference, ISC High Performance 2021, Virtual Event, June 24 – July 2, 2021, Proceedings
EditorsBradford L. Chamberlain, Ana-Lucia Varbanescu, Hatem Ltaief, Piotr Luszczek
Publication statusPublished - 17 Jun 2021
Event36th International Conference on High Performance Computing, ISC High Performance 2021 - Virtual, Online
Duration: 24 Jun 20212 Jul 2021

Publication series

NameLecture Notes in Computer Science (including subseries Lecture Notes in Artificial Intelligence and Lecture Notes in Bioinformatics)
ISSN (Print)0302-9743
ISSN (Electronic)1611-3349


Conference36th International Conference on High Performance Computing, ISC High Performance 2021
CityVirtual, Online