Dne neděle 04 Říjen 2009 05:09:51 Dane Springmeyer napsal(a): > I meant to ask if you had yet compared your generate_tiles.py > threading support to the recent additions in svn? > > I assume not since you wrote yours, as you say several months ago, but > it would be interesting to test the speed of each version.
Now I tried and the results are quite interesting. I tested on 3GHz Intel Core 2 Duo machine with 2GB RAM and using 2 threads. Result for OpenStreetMap generate_tiles.py was: real 42m10.608s user 21m39.037s sys 4m36.265s Result for OpenTrackMap (mine) generate_tiles.py was: real 56m57.562s user 32m7.568s sys 8m24.184s Then I noticed that OSM version doesn't use any overlapping. When I removed overlapping from mine version the result (even when full color version of tile is stored to the disk and then converted to 256 color version using ImageMagick) was: real 40m35.201s user 21m42.249s sys 6m42.197s Anyway, OSM version should use some overlapping because then there are some artifacts on tile borders. Maybe the best solution would be to render for example 16x16 (or more) tiles image with small border and then cut the image to separated tiles. This could bring also another performace gain because of better memory utilization or less access to DB. Mine version has small benefit compared to OSM version - it can be interrupted with CTRL+C keys, while mine version doesn't use job queue so it probably doesn't scale as well as OSM version. -- Ing. Radek Bartoň Faculty of Information Technology Department of Computer Graphics and Multimedia Brno University of Technology E-mail: black...@post.cz Web: http://blackhex.no-ip.org Jabber: black...@jabber.cz _______________________________________________ dev mailing list dev@openstreetmap.org http://lists.openstreetmap.org/listinfo/dev