On Nov 23, 2011, at 7:18 AM, Jed Brown wrote: > On Wed, Nov 23, 2011 at 05:43, Dominik Szczerba <dominik at itis.ethz.ch> > wrote: > In my procedure considerable time is spent to partition the domain. > When using MUMPS as a solver for my matrix I see the message: > > "Ordering based on METIS" > > This is an ordering to reduce fill in factorization, not to to partition the > domain. Last I heard, symbolic factorization was done in serial, which > explains why you find it taking a lot of time. The right hand side and > solution vectors are also passed on rank 0, which presents another > inefficiency/imbalance and memory bottleneck. Talk to the MUMPS developers or > use a different package if you don't like these properties.
Mumps does now have an option of parallel ordering. Run with -help and look at the options like -mat_mumps_icntl_28","ICNTL(28): use 1 for sequential analysis and ictnl(7) ordering, or 2 for parallel analysis and ictnl(29) ordering -mat_mumps_icntl_29","ICNTL(29): parallel ordering 1 = ptscotch 2 = parmetis I apologize that the options are organized in such a silly way but that is how MUMPS is organized. Barry
