That helped. I am also wondering about SEQ and MPI matrices, do they differ more than just in way of allocating data? When I run a small problem on 2 processes on single machine, it slows down greatly if I use
MatCreateMPIAIJ(PETSC_COMM_WORLD,PETSC_DECIDE,PETSC_DECIDE,n,n,5,PETSC_NULL,5,PETSC_NULL,&L); As I get mallocs during mat assembly while o_nz and d_nz are set to 5 where 5 is max nonzeros per whole row. I also get stash:0 assuring that values are set by correct process. Any hints on this one? Thank you Regards Bartek Wach The order or the way the values are inserted shouldn't matter. As long as the correct nozero structure is provided [with nnz] - there should be no additional mallocs. you can check with MatView() to see if the matrix is anyway different in the 2 cases. Satish -------------- next part -------------- An HTML attachment was scrubbed... URL: <http://lists.mcs.anl.gov/pipermail/petsc-users/attachments/20110526/8fb9fa67/attachment.htm>
