Michael L. Van De Vanter

Scientific Computing's Productivity Gridlock: How Software Engineering Can Help

Hardware improvements do little to improve real productivity in scientific programming. Indeed, the dominant barriers to productivity improvement are now in the software processes. To break the gridlock, we must establish a degree of cooperation and collaboration with the software engineering community that does not yet exist.

Can software engineering solve the HPCS problem

The High Productivity Computing Systems (HPCS) program seeks a tenfold productivity improvement. Software Engineering has addressed this goal in other domains and identified many important principles that, when aligned with hardware and computer science technologies, do make dramatic improvements in productivity. Do these principles work for the HPC domain?This case study collects data on the potential benefits of perfective maintenance in which human productivity (programmability, readability, verifiability, maintainability) is paramount. An HPC professional rewrote four FORTRAN77/MPI benchmarks in Fortran 90, removing optimizations (many improving distributed memory performance) and emphasizing clarity.The code shrank by 5-10x and is significantly easier to read and relate to specifications. Run time performance slowed by about 2x. More studies are needed to confirm that the resulting code is easy to maintain and that the lost performance can be recovered with compiler optimization technologies, run time management techniques and scalable shared memory hardware.