Always send output with -log_summary for each run that you do. On Thu, Feb 23, 2012 at 14:16, Francis Poulin <fpoulin at uwaterloo.ca> wrote:
> Hello, > > I am learning to use PetSc but am just a notice. I have a rather basic > question to ask and couldn't not find it on the achieves. > > I am wanting to test the scalability of a Multigrid solver to the 3D > Poisson equation. I found ksp/ex22.c that seems to solve the problem that > I'm interested in. I ran it on a large server using different processors. > > The syntax that I use to run using MPI was > > ./ex22 -da_grid_x 64 -da_grid_y 64 -da_grid_z 32 > Which version of PETSc? > > I tested it using 2, 4, 8, 16 cpus and found that the time increases. See > below. Clearly there is something that I don't understand since the time > should be reduced. > > n wtime > --------------------- > 2 3m58s > 4 3m54s > 8 5m51s > 16 7m23s > > Any advice would be greatly appreciated. > > Best regrads, > Francis > > > -------------- next part -------------- An HTML attachment was scrubbed... URL: <http://lists.mcs.anl.gov/pipermail/petsc-users/attachments/20120223/9bbe559b/attachment.htm>
