Hello Barry and Jed, Thanks a lot for the responses, Barry's in particular made me laugh. In my defence I did install v3.2 on my desktop but the server that I'm using only has v3.1 installed. I've asked them nicely if they can update it. If not I'll figure out a way of doing it myself. In the mean time I will do the testing in my desktop to set things up before I do serious runs on the big cluster. I will use ex45.c and the options that you both suggested. Thanks again for the help, Francis On 2012-02-23, at 11:30 PM, Barry Smith wrote:
On Feb 23, 2012, at 8:24 PM, Jed Brown wrote:
On Thu, Feb 23, 2012 at 18:58, Francis Poulin <[email protected]> wrote: 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..
There are only three levels. The coarsest level has 32k degrees of freedom, which is very expensive to solve (redundantly) with a direct solver.
Run this, it's higher resolution and will be much faster than what you had.
mpiexec -n 2 ./ex22 -da_grid_x 5 -da_grid_y 5 -da_grid_z 5 -dmmg_nlevels 6 -ksp_monitor -mg_levels_ksp_type richardson -mg_levels_pc_type sor -log_summary
Also, please switch to a more recent release of PETSc as soon as possible and do not develop new code using DMMG since that component has been removed (and its functionality incorporated into SNES and KSP).
Using Petsc Release Version 3.1.0, Patch 4, Fri Jul 30 14:42:02 CDT 2010
Goodness gracious, you won't run performance tests on your grandpa's desk calculator would you? Switch to petsc-dev immediately http://www.mcs.anl.gov/petsc/developers/index.html and use src/ksp/ksp/examples/tutorials/ex45.c and use the options -ksp_monitor -mg_levels_ksp_type richardson -mg_levels_pc_type sor -log_summary -da_refine 6
Barry