On Thu, Nov 10, 2011 at 12:30 PM, Bogdan Dita <bogdan at lmn.pub.ro> wrote:
> > Hello, > > Until a few days ago I've only be using PETSc in debug mode and when I > switch to the optimised version(--with-debugging=0) I got a strange > result regarding the solve time, what I mean is that it was 10-15 % > higher then in debug mode. > I'm trying to solve a linear system in parallel with superlu_dist, and > I've tested my program on a Beowulf cluster, so far only using a single > node with 2 quad-core Intel processors. > From what I know the "no debug" version should be faster and I know it > should be faster because on my laptop(dual-core Intel) for the same > program and even the same matrices the solve time for the optimised > version is 2 times faster, but when I use the cluster the optimised > version time is slower then the debug version. > My quess is that this has something to do with MPI. Any thoughts? > Performance questions are meaningless without the output of -log_summary for all cases. Matt > Best regards, > Bogdan Dita > -- What most experimenters take for granted before they begin their experiments is infinitely more interesting than any results to which their experiments lead. -- Norbert Wiener -------------- next part -------------- An HTML attachment was scrubbed... URL: <http://lists.mcs.anl.gov/pipermail/petsc-users/attachments/20111110/d42cb42b/attachment.htm>
