Monthly Archives: October 2015

Improving runtime performance

PCRaster Modflow groundwater model of Indonesia

During the summer we have been busy with tailoring PCRaster towards high-performance computing, and we already have rewritten parts of the PCRaster algorithms due to our Maps4Society project. This refactoring required significant efforts and code changes. Sometimes, however, appending just a single word can yield performance improvements as well… as our colleague Edwin Sutanudjaja mentioned, a simple NOPRINT statement in several packages prevents Modflow to write a large amount of redundant information. For a model running the extent shown above (see also here; 21600000 cells, with 3920887 drains and 21600000 river cells) the Modflow runtime reduces from about

real 5m39.229s
user 5m10.392s
sys 0m25.511s

to about

real 3m33.181s
user 3m1.913s
sys 0m25.666s

Nice savings, especially if you need to run several timesteps! The improvements will be included in the upcoming PCRaster release.