[GRASS-dev] [GRASS GIS] #2750: LZ4 when writing raster rows; better than double I/O bound r.mapcalc speed

GRASS GIS trac at osgeo.org
Thu Feb 18 14:45:05 PST 2016


#2750: LZ4 when writing raster rows; better than double I/O bound r.mapcalc speed
--------------------------+---------------------------
  Reporter:  sprice       |      Owner:  grass-dev@…
      Type:  enhancement  |     Status:  new
  Priority:  normal       |  Milestone:  7.1.0
 Component:  Raster       |    Version:  svn-trunk
Resolution:               |   Keywords:  ZLIB LZ4 ZSTD
       CPU:  OSX/Intel    |   Platform:  MacOSX
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Comment (by mmetz):

 Replying to [comment:41 neteler]:
 >
 > Overall, ZLIB at Level 1 performs well followed by LZ4 (BZIP2 compresses
 best but was very slow; ZLIB level 6's small size gain over ZLIB level 1
 is "paid" by performance).

 Now we have compression options for different use cases. For large raster
 maps (many columns, e.g. + 20,000), BZIP2 should provide the best
 compression and should require the least disk space. If disk space
 consumption and I/O speed do not matter, LZ4 could be used. The best
 compression method depends on the size of the raster to be compressed, the
 I/O reading and writing speed, and the available storage capacity. ZLIB
 level 1 provides a pretty good compromise. Optimizing raster map
 compression is now possible but requires testing with the current raster
 map(s) and the available storage infrastructure (I/O speed + capacity).

 TODO: documentation + r.compress

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Ticket URL: <https://trac.osgeo.org/grass/ticket/2750#comment:43>
GRASS GIS <https://grass.osgeo.org>



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