On Jul 27, 2010, at 4:19 PM, Gus Correa wrote: > Is there a simple way to check the number of bytes associated to each > MPI basic type of OpenMPI on a specific machine (or machine+compiler)? > > Something that would come out easily, say, from ompi_info?
Not via ompi_info, but the MPI function MPI_GET_EXTENT will tell you the datatype's size. ----- [4:54] svbu-mpi:~/mpi % cat extent.f90 program main use mpi implicit none integer ierr, ext call MPI_INIT(ierr) call MPI_TYPE_EXTENT(MPI_DOUBLE_PRECISION, ext, ierr) print *, 'Type extent of DOUBLE_PREC is', ext call MPI_FINALIZE(ierr) end [4:54] svbu-mpi:~/mpi % mpif90 extent.f90 -o extent -g [4:54] svbu-mpi:~/mpi % ./extent Type extent of DOUBLE_PREC is 8 [4:54] svbu-mpi:~/mpi % ----- -- Jeff Squyres jsquy...@cisco.com For corporate legal information go to: http://www.cisco.com/web/about/doing_business/legal/cri/