TY - JOUR
AU - Schöbel, Ruth
AU - Speck, Robert
TI - PFASST-ER: combining the parallel full approximation scheme in space and time with parallelization across the method
JO - Computing and visualization in science
VL - 23
IS - 1-4
SN - 1432-9360
CY - Heidelberg
PB - Springer
M1 - FZJ-2020-03974
SP - 12
PY - 2020
AB - To extend prevailing scaling limits when solving time-dependent partial differential equations, the parallel full approximation scheme in space and time (PFASST) has been shown to be a promising parallel-in-time integrator. Similar to space–time multigrid, PFASST is able to compute multiple time-steps simultaneously and is therefore in particular suitable for large-scale applications on high performance computing systems. In this work we couple PFASST with a parallel spectral deferred correction (SDC) method, forming an unprecedented doubly time-parallel integrator. While PFASST provides global, large-scale “parallelization across the step”, the inner parallel SDC method allows integrating each individual time-step “parallel across the method” using a diagonalized local Quasi-Newton solver. This new method, which we call “PFASST with Enhanced concuRrency” (PFASST-ER), therefore exposes even more temporal concurrency. For two challenging nonlinear reaction-diffusion problems, we show that PFASST-ER works more efficiently than the classical variants of PFASST and can use more processors than time-steps.
LB - PUB:(DE-HGF)16
UR - <Go to ISI:>//WOS:000572641700001
DO - DOI:10.1007/s00791-020-00330-5
UR - https://juser.fz-juelich.de/record/885633
ER -