Re: [petsc-users] Error using GPU in Fortran code

2023-08-31 Thread Ramoni Z. Sedano Azevedo
Thank you all for the answers. I've just started in a group where the code has been running for some time on the CPU and we started trying to run it on the GPU to see a processing gain. I'm going to talk here about the points you've already raised. Thank you very much! Em qui., 31 de ago. de 20

Re: [petsc-users] Error using GPU in Fortran code

2023-08-30 Thread Barry Smith
Yikes, sorry I missed that the first run was CPU and the second GPU. The run on the CPU is indicative of a very bad preconditioner. It doesn't really converge. When the true residual norm jumps by a factor of 10^3 at the first iteration, this means the ILU preconditioner is just not approp

Re: [petsc-users] Error using GPU in Fortran code

2023-08-30 Thread Junchao Zhang
On Wed, Aug 30, 2023 at 8:46 PM Barry Smith wrote: > >What convergence do you get without the GPU matrix and vector > operations? Barry, that was in the original email > > >Can you try the GPU run with -ksp_type gmres -ksp_pc_side right ? > >For certain problems, ILU can produce cat

Re: [petsc-users] Error using GPU in Fortran code

2023-08-30 Thread Barry Smith
What convergence do you get without the GPU matrix and vector operations? Can you try the GPU run with -ksp_type gmres -ksp_pc_side right ? For certain problems, ILU can produce catastrophically bad preconditioners. Barry > On Aug 30, 2023, at 4:41 PM, Ramoni Z. Sedano Azevedo

Re: [petsc-users] Error using GPU in Fortran code

2023-08-30 Thread Junchao Zhang
Hi, Ramoni Do you have a reproducible example? Usually it is because the cpu and gpu are out of synchronization. It could be a user's problem or petsc's. Thanks. --Junchao Zhang On Wed, Aug 30, 2023 at 4:13 PM Ramoni Z. Sedano Azevedo < ramoni.zsed...@gmail.com> wrote: > Hello, > > I'm exe

[petsc-users] Error using GPU in Fortran code

2023-08-30 Thread Ramoni Z. Sedano Azevedo
Hello, I'm executing a code in Fortran using PETSc with MPI via CPU and I would like to execute it using GPU. PETSc is configured as follows: ./configure \ --prefix=${PWD}/installdir \ --with-fortran \ --with-fortran-kernels=true \ --with-cuda \ --download-fblaslapack \ --with-scalar-type=co