Brian Powell wrote:
> I ran a final test which I find very strange: I ran the same test case
> on 1 cpu. The MVAPICH2 case was 23% faster!?!? This makes little sense
> to me. Both are using ifort as the mpif90 compiler using *identical*
> optimization flags, etc. I don't understand how the results could be
Are you saying the output of mpicc/mpif90 -show has the same
optimization flags? MPICH2 usually puts it's own optimization flags
into the wrappers.