GeoPar library

In cooperation with IBM's Heidelberg Scientific and Technical Centre (HDSTC), a program library (GeoPar) was developed for parallelisation of problems on grids with limited scope of interaction. The library was designed for the IBM RS/6000 SP parallel computer, which is based on a distributed memory architecture. The data exchange and synchronisation is managed by a special high-speed network (high-performance switch). Parallelisation is accomplished on the software side by means of the message-passing paradigm using the MPI standard. The library is written in C, an interface to FORTRAN/FORTRAN90 is provided. A manual can be found here. A similar approach was followed by the Global array toolkit developed at the William R. Wiley Environmental Molecular Sciences Laboratory (EMSL). The GeoPar library was applied to the field of geophysiological modelling ("Daisyworld").

Parallelization of networks

A parallel library has been developed for the parallelisation of networks. The parallel algorithm has been used for the river routing part (with a tree topology) of a dynamic global vegetation model (LPJmL). Communication within the library is performed by the collective operation MPI_Alltoallv of the message-passing interface MPI.

Documentation

• MPI-2 - Extensions to the message passing interface (Postscript file)
• OpenMP for Fortran - Shared memory programming model (PDF-file)
• OpenMP for C,C++ - Shared memory programming model (PDF-file)

Links

• Software descriptions
  • Homepage of the MPI forum
  • Homepage of the OpenMP Architecture Review Board
  • Global Array Toolkit - "shared memory" interface for distributed-memory computers based on MPI
• Computing and research sites
  • ZIB - Zuse Center for Scientific Computing Berlin
  • DKRZ - Deutsches Klimarechenzentrum Hamburg
  • GWDG - Gesellschaft für wissenschaftliche Datenverarbeitung Göttingen
  • RZG - Rechenzentrum Garching at the Max-Planck-Institut für Plasmaphysik (IPP)
  • HLRN - Norddeutscher Verbund für Hoch- und Höchstleistungsrechnen
  • NIC - John von Neumann-Institut für Computing, Jülich
  • TOP500 Supercomputer sites presented by the University of Mannheim and University of Tennessee