PMPIO-a portable implementation of MPI-IO

MPI-IO provides a demonstrably efficient portable parallel Input/Output interface, compatible with the MPI standard. PMPIO is a "reference implementation" of MPI-IO, developed at NASA Ames Research Center. To date, PMPIO has been ported to the IBM SP-2, SGI and Sun shared memory workstations, the Intel Paragon, and the Cray J90. Preliminary results using the PMPIO implementation of MPI-IO show an improvement of as much as a factor of 20 on the NAS BTIO benchmark compared to a Fortran based implementation. We show comparative results on the SP-2 Paragon, and SGI architectures.