[gdal-dev] Re: Integer error in creating bigtiff image

[Hermann Peifer]

On 24/08/2010 21:33, Even Rouault wrote:

>
> Try reducing under 2000 and it should work better. A too big value for the -wm
> parameter can even sometimes affect speed negatively, and that'd probably the
> case for your example where you are merging a lot of individual files into a
> big one.
>

Just to add that this counter-intuitive behaviour is mentioned at:
http://trac.osgeo.org/gdal/wiki/UserDocs/GdalWarp#WillincreasingRAMincreasethespeedofgdalwarp

You could use: --debug on, and then observe how Src and Dst windows 
change depending on the chosen -wm value. (There is little point in 
having the Src window bigger than the input raster.)

Hermann