From: tcclevenger Date: Mon, 1 Jun 2020 23:55:19 +0000 (-0400) Subject: step-50 and Stokes text X-Git-Url: https://gitweb.dealii.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=e966d60d424c5b642987c01f244352b2ada1be75;p=release-papers.git step-50 and Stokes text --- diff --git a/9.2/paper.tex b/9.2/paper.tex index 4d19cff..3cb9424 100644 --- a/9.2/paper.tex +++ b/9.2/paper.tex @@ -531,8 +531,11 @@ the setup of the multigrid transfer. \end{figure} -As part of this effort, we ran benchmarks on the TACC Frontera system, where we were able to apply the matrix-free geometric multigrid framework to a variable viscosity Stokes system and achieved weak and strong scaling up to 114k MPI ranks with up to -\num{2.1e11} unknowns. This is likely the currently largest block system solved with \dealii{} and required various optimizations +As part of this effort, we ran benchmarks on the TACC Frontera system, where we were +able to apply the matrix-free geometric multigrid framework to a variable viscosity +Stokes system and achieved weak and strong scaling up to 114K MPI ranks with up to +\num{2.1e11} unknowns. This is likely the largest block system currently solved with +\dealii{} and required various optimizations and fixes on top of the ones mentioned above: (i) Bug fixes to concurrent point to point communications. (ii) Fixes multigrid transfer with adaptive refinement and more than \num{4e9} unknowns. @@ -946,11 +949,13 @@ In addition, there are a number of new tutorial programs: in \dealii{} as described in \cite{ClevengerHeisterKanschatKronbichler2019}. The problem considered is a variable viscosity Laplace equation and it is solved with three different approaches: - (i) With a matrix-based geometric multigrid based on Trilinos or - PETSc; (ii) with a matrix-free - geometric multigrid; (iii) using algebraic multigrid (Trilinos ML). + (i) using a matrix-based geometric multigrid based on Trilinos or + PETSc; (ii) using a matrix-free + geometric multigrid; (iii) using algebraic multigrid (Trilinos ML). The tutorial + demonstrates the superiority of the matrix-free method for the problem under consideration, + and shows that, for matrix-based formulations, the performance of algebraic and + geometric multigrid methods are roughly comparable. - \todo[inline]{Timo/Conrad/... to write} \item \texttt{step-58} is a program that solves the nonlinear Schr{\"o}dinger equation, which in non-dimensional form reads