[gdal-dev] warp memory limit default too low and does not have a config option

[Etienne Tourigny]

Hi all,

The default memory limit for warp operations is 64MB, which is far too
low using recent hardware and leads to inefficiencies in I/O when
warping large images.

This can be changed using the -wm option of gdalwarp, or if using the
API change the value of GDALWarpOptions::dfWarpMemoryLimit.
More information here:
http://trac.osgeo.org/gdal/wiki/UserDocs/GdalWarp#WillincreasingRAMincreasethespeedofgdalwarp

However, it would be better to do both of the following:

1) Change the default value of 64 MB to something higher, perhaps
depending on the machine's configuration (say 1/4 of RAM) - this
possibility is mentioned in gdalwarpoperation.cpp  .
2) Add a config option so that the default can be set for all
operations by the user (which overrides 1, but can be overridden for
each operation)


Any comments?

regards,
Etienne