[magick-users] HP Core Duo freezeup

[omicronpersei8 at imagemagick.org]

> At unpredictable intervals, and on different files, convert hangs

Add -debug cache to your command line.  Most likely your image is being
cached to disk which can be 1000 times slower than in-memory conversion.
Otherwise the conversion is taking place in memory and your system is
thrashing.  For predictable but slower results, add -limit area 2048 to
your command line.  This forces large images to be cached to disk.