Hi Gerd, I think it's even more in combination with DEM. I usually use 6 of my 8 cores and ending up with 10 to 12 GB of heap. So I definitely agree with you available heap somehow needs to be considered as well. Not only CPU cores. Btw. for CFD/FEM analysis the simulation is usually is faster if you only use physical cores, not the 'virtual' ones. Don't know how mkgmap will behave.
Henning On 05.02.2018 15:28, Gerd Petermann wrote: > Hi Mike, > > thought about this again. Maybe this change is too simple. With multiple jobs > one also > needs more heap (-Xmx JRE option). If you create rather large tiles with > splitter (max-nodes=1600000) > you need 0.5 - 1 GB for each job. Not sure what happens when a user creates a > map with > 10 tiles on an 8-core machine without any -Xmx option. > > I fear this will result in OutOfMemory exception, so better check the > available heap as well. > > Gerd > > ________________________________________ > Von: mkgmap-dev <mkgmap-dev-boun...@lists.mkgmap.org.uk> im Auftrag von Mike > Baggaley <m...@tvage.co.uk> > Gesendet: Sonntag, 4. Februar 2018 15:14 > An: 'Development list for mkgmap' > Betreff: [mkgmap-dev] max-jobs patch > > Hi Gerd, > > Please find attached a patch that amends the default behaviour if the > --max-jobs option is not specified, to using a value equal to the number of > CPU cores, as suggested in a previous post. The documentation is also > amended to reflect the change. This halves the execution time of mkgmap for > building a map of Staffordshire on my 8-core PC when --max-jobs is not > specified (I didn't know about this option previously and was unaware the > performance could have been improved). > > Cheers, > Mike > _______________________________________________ > mkgmap-dev mailing list > mkgmap-dev@lists.mkgmap.org.uk > http://www.mkgmap.org.uk/mailman/listinfo/mkgmap-dev > _______________________________________________ mkgmap-dev mailing list mkgmap-dev@lists.mkgmap.org.uk http://www.mkgmap.org.uk/mailman/listinfo/mkgmap-dev