Imagemagik version

[magick]

You could try the latest ImageMagick release, 6.2.9-8, which users have reported to be faster than earlier releases of ImageMagick. If you find it still is slower than ImageMagick 5.5.7 let us know what command you are using so we can reproduce the problem and track a solution.

[anthony]

It may also be that the speed decrease was caused by some major improvement in porcess handling, however reporting what was faster and what was not will let us track performance issues.