openCL slows down complex command

[adam7288]

Hello - I clearly am in over my head. Before I invest in multi core CPU's to address my needs, I want to make sure I there is no way to speed up the following command (for processing images to fax format):

convert <filename> -auto-orient -background "#FFFFFF" -resize 1728x2200 -gravity center -extent 1728x2200 -monochrome -threshold 80% -despeckle -depth 1 -set units PixelsPerInch -density 204x196 -compress FAX -format tiff <outputfilename>

When I compile for OpenCL on a newish (Geforce 960) gpu, the command executes 5x slower. Would be great if I could speed this up using gpu power instead of buying lots of cpus.

[adam7288]

Update: I compiled with debug on.

Once I compile for "release" the result is that OpenCL does not get used in the above command. Any way to have imagemagick get used to speed it up?