Hi, it is easy to change the HashMap<Long,Coord> coordMap in ElementSaver to use the OSMId2ObjectMap that I've implemented for splitter. This could reduce peak memory usage in mkgmap. A few numbers according to VisualVM: 2.248.404 coord instances managed in the HashMap req. 186.447.135 bytes, with OSMId2ObjectMap it is 57.194.684. This doesn't include the memory that is needed to store the Coord instances itself, (which I think is 2.248.404 * 32 = 71.948.928 bytes) it is just the overhead for the map. The disadvantage: OSMId2ObjectMap uses fastutil.jar, which is not used in mkgmap until now. I could try to change OSMId2ObjectMap so that it runs without fastutil.jar, but that would mean to invent the wheel again. Comments? Gerd -- View this message in context: http://gis.19327.n5.nabble.com/Possible-memory-reduction-in-mkgmap-tp5743567... Sent from the Mkgmap Development mailing list archive at Nabble.com.