Hi Razi, I have tested both atlas and other blas/lapack and found small effects on linux.
For using ATLAS with petsc, you configure ATLAS, build it, and then specify when you configure petsc --with-blas-lapack-dir= where your ATLAS libs are. In my case, I use --with-blas-lapack-dir=/usr/local/ATLAS/Linux_X86_64/ Good luck, Berend. > > I have a couple questions about the PETSc performance: > > Does having ATLAS ( math-atlas.sourceforge.net ) help ? If so how do I > hook it to PETSc ? > > How do I best customize the compiler flags? Should I edit the > variables directly in petscconf, or can I do it with configure ? > > > Thanks, > > Razi >
