Nek5000 with OpenACC
2015 (English)In: Solving software challenges for exascale, 2015, 57-68 p.Conference paper (Refereed)
Nek5000 is a computational fluid dynamics code based on the spectral element method used for the simulation of incompressible flows. We follow up on an earlier study which ported the simplified version of Nek5000 to a GPU-accelerated system by presenting the hybrid CPU/GPU implementation of the full Nek5000 code using OpenACC. The matrix-matrix multiplication, the Nek5000 gather-scatter operator and a preconditioned Conjugate Gradient solver have implemented using OpenACC for multi-GPU systems. We report an speed-up of 1.3 on single node of a Cray XK6 when using OpenACC directives in Nek5000. On 512 nodes of the Titan supercomputer, the speed-up can be approached to 1.4. A performance analysis of the Nek5000 code using Score-P and Vampir performance monitoring tools shows that overlapping of GPU kernels with host-accelerator memory transfers would considerably increase the performance of the OpenACC version of Nek5000 code.
Place, publisher, year, edition, pages
2015. 57-68 p.
, Lecture Notes in Computer Science, ISSN 0302-9743 ; 8759
GPU programming, Nek5000, OpenACC, Spectral element method
IdentifiersURN: urn:nbn:se:kth:diva-170716DOI: 10.1007/978-3-319-15976-8_4ISI: 000355749700004ScopusID: 2-s2.0-84928882903ISBN: 978-3-319-15975-1ISBN: 978-3-319-15976-8OAI: oai:DiVA.org:kth-170716DiVA: diva2:839926
2nd International Conference on Exascale Applications and Software (EASC), APR 02-03, 2014, Stockholm, SWEDEN
QC 201507062015-07-062015-07-032015-07-06Bibliographically approved