Jorgen Moth,
UNI-C, The Danish Computing Centre for Research and Education, DTU,
Building 304, DK-2800 Lyngby, Denmark.
jorgen.moth@uni-c.dk
A real world full 3D Navier-Stokes code to study the behaviour of wind turbine rotor blades has been parallelised with HPF. Crucial sections of this 20.000+ lines of traditional Fortran77 style code was first transformed manually into Fortran90 style to allow for automatic parallelisation by the HPF compilation and runtime system. Issues of strategies to carry scientific production codes from the previous Fortran77 world to the new Fortran90/95 world taking advantage of the parallelisation capabilities of the HPF additions will be covered as well as the different HPF parallelisation techniques of choosing from among genuine HPF subroutines versus local and "pure" subroutines. The choice of subroutine method may have an impact on the requirements for code re-writing and also on the code performance. A major objective of this project has been to achieve a comfortable speed-up of the program when run on our 88 node IBM RS/6000 SP parallel computer still keeping the number of changes to the original code at a modest level.
The work was carried out using Portland Group Inc. HPF compilation system running on the above mentioned parallel IBM system and while developing and testing also on an 8 node PC linux cluster. Performance measurements and comparisons between these systems will be shown.