Re: [petsc-users] Using PETSc GPU backend

Mark. The FEM problem is of high-frequency Helmholtz type for the Maxwell equation. The combination "-ksp_type groppcg -pc_type gamg" worked for this small problem and the results agreed well with those obtained from the direct solver MUMPS. However, this ksp-pc combination failed to converge f

Re: [petsc-users] Using PETSc GPU backend

As Barry said, this is a bit small but the performance looks reasonable. The solver does very badly, mathematically. I would try hypre to get another data point. You could also try 'cg' to check that the pipelined version is not a problem. Mark On Fri, Apr 12, 2024 at 3:54 PM Barry Smith wrote:

Re: [petsc-users] Using PETSc GPU backend

800k is a pretty small problem for GPUs. We would need to see the runs with output from -ksp_view -log_view to see if the timing results are reasonable. > On Apr 12, 2024, at 1:48 PM, Ng, Cho-Kuen wrote: > > I performed tests on comparison using KSP with and without cuda backend on > NE

Re: [petsc-users] Using PETSc GPU backend

I performed tests on comparison using KSP with and without cuda backend on NERSC's Perlmutter. For a finite element solve with 800k degrees of freedom, the best times obtained using MPI and MPI+GPU were o MPI - 128 MPI tasks, 27 s o MPI+GPU - 4 MPI tasks, 4 GPU's, 32 s Is that the performance

Re: [petsc-users] MatCreateTranspose

> On 12 Apr 2024, at 11:51 AM, Carl-Johan Thore > wrote: > > On Fri, Apr 12, 2024 at 11:16 AM Pierre Jolivet > wrote: >> >> >>> On 12 Apr 2024, at 11:10 AM, Carl-Johan Thore >> > wrote: >>> >>> Pierre, I see that you've already done

Re: [petsc-users] MatCreateTranspose

On Fri, Apr 12, 2024 at 11:16 AM Pierre Jolivet wrote: > > > On 12 Apr 2024, at 11:10 AM, Carl-Johan Thore > wrote: > > Pierre, I see that you've already done a merge request for this. Thanks! > I have tested this and it works nicely in my application > > > I guess your matrix is symmetric in pa

Re: [petsc-users] MatCreateTranspose

> On 12 Apr 2024, at 11:10 AM, Carl-Johan Thore > wrote: > > Pierre, I see that you've already done a merge request for this. Thanks! > I have tested this and it works nicely in my application I guess your matrix is symmetric in pattern? Because otherwise, I don’t think this should work. But

Re: [petsc-users] MatCreateTranspose

Pierre, I see that you've already done a merge request for this. Thanks! I have tested this and it works nicely in my application /Carl-Johan On Wed, Apr 10, 2024 at 8:24 AM Carl-Johan Thore wrote: > > > On Tue, Apr 9, 2024 at 5:31 PM Pierre Jolivet wrote: > >> >> On 9 Apr 2024, at 4:19 PM, Car