Jukka Rahkonen <jukka.rahkonen <at> mmmtike.fi> writes:
> I borrowed my son's computer and made one more test. Important numbers about the > computer: > Windows 7, 64 -bit > Four-core Intel i5 2500k @3,3 GHz > SSD disk > > Timings for germany.osm.pbf by using -lco SPATIAL_INDEX=NO. Times are total > times from the beginning of the test > > 70% progress - 5 minutes (I suppose resolving ways begins about at this > phase) > 100 % progress - 17 minutes > manual index creation for all the layers ready - 45 minutes > > Results are interesting. Import to Spatialite without indexing was six times > faster for me and I suppose it is mostly because of the SSD drive. But creating > indexes took me 30 minutes while you timing was 22 minutes. Perhaps there is > something sub-optimal in combination of Windows/Spatialite/Create spatial index. > > Anyway, the score for germany.osm.pbf is now 45 minutes. Someone with Linux and > SSD drive is perhaps the one to beat the record. > > For comparison, converting finland.osm.pbf took 2 min 40 sec. Converting Germany > took 20 times more time and I believe that the relation is OK now. Another set of tests with a brand new and quite powerful laptop. Specs for the computer: Intel i7-2760QM @2.4 GHz processor (8 threads) Hitachi Travelstar Z7K320 7200 rpm SATA disk 8 GB of memory Windows 7, 64-bit GDAL-version r24717, Win64 build from gisinternals.com Timings for germany.osm.pbf (1.3 GB) ==================================== A) Default settings with command ogr2ogr -f sqlite -dsco spatialite=yes germany.sqlite germany.osm.pbf -gt 20000 -progress --config OGR_SQLITE_SYNCHRONOUS OFF - reading the data 67 minutes - creating spatial indexes 38 minutes - total 105 minutes B) Using in-memory Spatialite db for the first step by giving SET OSM_MAX_TMPFILE_SIZE=7000 - reading the data 16 minutes - creating spatial indexes 38 minutes - total 54 minutes Peak memory usage during this conversion was 4.4 GB. Conclusions =========== * The initial reading of data is heavily i/o bound. This phase is really fast if there is enough memory for keeping the OSM tempfile in memory but SSD disk seems to offer equally good performance. * Creating spatial indexes for the Spatialite tables is also i/o bound. The hardware sets the speed limit and there are no other tricks for improving the performance. Multi-core CPU is quite idle during this phase with 10-15% load. * If user does not plan to do spatial queries then then it may be handy to save some time and create the Spatialite db without spatial indexes by using -lco SPATIAL_INDEX=NO option. * Windows disk i/o may be a limiting factor. I consider that for small OSM datasets the speed starts to be good enough. For me it is about the same if converting the Finnish OSM data (137 MB in .pbf format) takes 160 or 140 seconds when using the default settings or in-memory temporary database, respectively. -Jukka Rahkonen- _______________________________________________ gdal-dev mailing list gdal-dev@lists.osgeo.org http://lists.osgeo.org/mailman/listinfo/gdal-dev