Thanks Satish, And yes I meant sequentially.
On Wed, Jan 13, 2016 at 8:26 PM, Satish Balay <ba...@mcs.anl.gov> wrote: > On Wed, 13 Jan 2016, Justin Chang wrote: > > > Hi all, > > > > What exactly is the difference between these two preconditioners? When I > > use them to solve a Galerkin finite element poisson problem, I get the > > exact same performance (iterations, wall-clock time, etc). > > you mean - when you run sequentially? > > With block jacobi - you decide the number of blocks. The default is > 1-block/proc > i.e - for sequnetial run you have only 1block i.e the whole matrix. > > So the following are essentially the same: > -pc_type bjacobi -pc_bjacobi_blocks 1 [default] -sub_pc_type ilu [default] > -pc_type ilu > > Satish > > > Only thing is I can't seem to use ILU in parallel though. > >
