Basic HTML version of Foils prepared May 12 1996

Foil 29 HPF: Some Problems we found

From Overview of HPCC Applications at NPAC CRPC Annual Meeting -- May 14-17 1996. by Geoffrey Fox


We find that our best results with HPF codes come from those designed as parallel codes.
Traditional Model of "dusty deck + HPF directives" often does not work well.
Is not as intuitive as expected. Students have problems with getting performance. Reasons:
  • Poor knowledge of Fortran 90.
  • Many "details" are not handled well without some code massaging. Often HPF actions are highly non intuitive for inexperienced users.
  • Poor and cryptic compiler diagnostics and feedback.
  • Profilers (both PGI and DEC) help to identify sources of inefficiencies, though.



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