Speck, RobertRobertSpeckRuprecht, DanielDanielRuprechtEmmett, MatthewMatthewEmmettBolten, MatthiasMatthiasBoltenKrause, RolfRolfKrause2021-10-192021-10-192014Proceedings of the International Conference on Parallel Programming, ParCo 2013. - Amsterdam : IOS Press, 2013. - (Advances in Parallel Computing ; 25). - Pp. 263-272 (2014)http://hdl.handle.net/11420/10556The paper presents a combination of the time-parallel "parallel full approximation scheme in space and time" (PFASST) with a parallel multigrid method (PMG) in space, resulting in a mesh-based solver for the three-dimensional heat equation with a uniquely high degree of efficient concurrency. Parallel scaling tests are reported on the Cray XE6 machine "Monte Rosa" on up to 16,384 cores and on the IBM Blue Gene/Q system "JUQUEEN" on up to 65,536 cores. The efficacy of the combined spatial-and temporal parallelization is shown by demonstrating that using PFASST in addition to PMG significantly extends the strong-scaling limit. Implications of using spatial coarsening strategies in PFASST's multi-level hierarchy in large-scale parallel simulations are discussed. © 2014 The authors and IOS Press.en3D heat equationJUQUEENMonte Rosamulti-level spectral deferred correctionparallel multigridparallel-in-time integrationPFASSTInformatikConference Paper10.3233/978-1-61499-381-0-263Other