Hello Barry, I can do it for each of them if that helps but I suspect the method is the same so I'm sending the information for the first 3, n = 2, 4, 8. In the mean time I will figure out how to change the number of levels..
Thanks, Francis -------------- next part -------------- An embedded and charset-unspecified text was scrubbed... Name: saw_log_summary_n8_info.txt URL: <http://lists.mcs.anl.gov/pipermail/petsc-users/attachments/20120223/2dd782fe/attachment-0003.txt> -------------- next part -------------- An embedded and charset-unspecified text was scrubbed... Name: saw_log_summary_n4_info.txt URL: <http://lists.mcs.anl.gov/pipermail/petsc-users/attachments/20120223/2dd782fe/attachment-0004.txt> -------------- next part -------------- An embedded and charset-unspecified text was scrubbed... Name: saw_log_summary_n2_info.txt URL: <http://lists.mcs.anl.gov/pipermail/petsc-users/attachments/20120223/2dd782fe/attachment-0005.txt> -------------- next part -------------- On 2012-02-23, at 4:20 PM, Barry Smith wrote: > > Still need the -ksp_view output. It is spending most of the time in the LU > factorization and solve. I suspect the coarse problem is way to big (like you > are using two levels of multigrid) and since it is solved redundantly that > takes all the time. Run with say 5 levels. > > Barry > > On Feb 23, 2012, at 3:03 PM, Francis Poulin wrote: > >> Hello again, >> >> I am using v3.1 of PETSc. >> >> I changed the grid sizes slightly and I'm including 4 log_summary files. >> >> The times are shown below. I have not modified the example at all except in >> specifying the matrix size. Could it be that I need much larger? When I >> tried much larger matrices I think I might have got an error because I was >> using too much memory. >> >> n time >> 2 22s >> 4 29.8s >> 8 33.7s >> 16 28.3s >> >> Sorry for my first email but I hope this has more information. >> >> Cheers, Francis >> >> >> <saw_log_summary_n2.txt> >> <saw_log_summary_n4.txt> >> <saw_log_summary_n8.txt> >> <saw_log_summary_n16.txt> >>> >> >> On 2012-02-23, at 3:27 PM, Jed Brown wrote: >> >>> 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 >>> >>> >>> >> >
