WoW ! Thanks Markus ! On 30 July 2014 21:42, Markus Neteler <nete...@osgeo.org> wrote: > Hi, > > I have made a modification to r.in.gdal for a (significant) speedup > (both in trunk and relbranch70). > > A nice test case is the European 25m elevation model which is a 23GB > GeoTIFF file of 4.8 billion raster cells: > > gdalinfo /geodata/eudem_dem_3035_europe.tif > Driver: GTiff/GeoTIFF > Files: /geodata/eudem_dem_3035_europe.tif > Size is 240000, 200000 > Coordinate System is: > PROJCS["ETRS89 / LAEA Europe", > ... > UNIT["metre",1, > AUTHORITY["EPSG","9001"]], > AUTHORITY["EPSG","3035"]] > ... > Pixel Size = (25.000000000000000,-25.000000000000000) > ... > > Previously: > # using default GDAL cache (~40MB, which is tiny also for gdalwarp etc!) > GRASS 7.0.0svn (eu_laea):~ > time -p r.in.gdal > /geodata/eudem_dem_3035_europe.tif \ > output=eudem_dem_3035_europe > 100% > Raster map <eudem_dem_3035_europe> created. > r.in.gdal complete. > real 279901.23 > user 267876.52 > sys 1456.18 > --> 77h > > New: > # I have now defined 300MB as default cache size (i.e. memory=300) > GRASS 7.0.0svn (eu_laea):~ > time -p r.in.gdal > /geodata/eudem_dem_3035_europe.tif \ > output=eu_dem_25m > 100% > Raster map <eu_dem_25m> created. > r.in.gdal complete. > real 5381.95 > user 5091.27 > sys 31.03 > --> 1:30h > > The user can set different cache sizes via the memory option as > before. Most probably didn't know about this huge difference, that's > why I added 300MB as default cache size (rather than keeping the > original tiny GDAL setting [1]). > > If I am not wrong, it took only 2% of the previous time for importing > this big file. > Perhaps the GDAL project should reconsider their default cache size as well > :-) > > enjoy, > Markus > > [1] http://trac.osgeo.org/gdal/wiki/ConfigOptions#GDAL_CACHEMAX > _______________________________________________ > grass-dev mailing list > grass-dev@lists.osgeo.org > http://lists.osgeo.org/mailman/listinfo/grass-dev
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