The tile splitter always compresses its output files. It is unnecessary if you need the output files for some preprocessing in an uncompressed form anyway. Besides it is slightly faster without compression. The attached patch adds a switch "--compressed=false" to switch off the compression. Some performance comparisons on the germany.osm.bz2 file from the Geofabrik: All runs are with -Xms2048m -Xmx2048m --compressed=true Total time 3723s real 62m4.775s user 34m26.067s sys 25m55.815s --compressed=false Total time 3574s real 59m34.642s user 31m7.879s sys 26m9.109s Only about 5% better performance without compression. YMMV. Best regards Thilo