Hello Matt,
> > That stuff is rarely worth running. Without a decent model of the > performance, the > data is no help. I am not talking about network bandwidth, but > memory bandwidth. > For a sparse matvec that comes from a simple scalar PDE, you need > incredible > amounts of bandwidth to drive the tiny amount of flops. The equation > is in the paper. > >> Please see the paper >> by Kaushik and Gropp which models sparse matvec performance (on >> Dinesh's website). >> >> Which Paper on which website. Please send a link. > > I believe you want 11 and 17 here http://www.mcs.anl.gov/~kaushik/ > under the Publications link. Got it. I will look at it and check the memory bandwidth > > >> 3) You would see better performance using a block method. Sparse >> matvec >> without >> blocks will never see good percentages of peak (ditto for >> backsolve). >> >> How do I use the block methods? >> Since I rely on the "user-level" interfaces kspsolve etcpp., I >> don't see how >> i could influence this. > > You can't unless your system has block structure. If it does, you can > use the BAIJ > matrix types. I'll try it. Thank you for your advice that far. Sincerly, Christoph > -------------- next part -------------- An HTML attachment was scrubbed... URL: <http://lists.mcs.anl.gov/pipermail/petsc-users/attachments/20081013/682f93d7/attachment.htm> -------------- next part -------------- A non-text attachment was scrubbed... Name: PGP.sig Type: application/pgp-signature Size: 194 bytes Desc: This is a digitally signed message part URL: <http://lists.mcs.anl.gov/pipermail/petsc-users/attachments/20081013/682f93d7/attachment.pgp>
