You can test hyperthreading performance with the -bench option and OpenMP. It shows that ImageMagick, in general, does not benefit much from hyperthreading, but like any benchmark it depends on what you're doing. The only way to tell is to run your command with the -bench option with hyperthreading on and then off and compare the timing. The -bench option benchmarks your command line and shows efficiency for the number of threads from 1 to the number of cores ( x 2 for hyperthreading). Typically you will see an efficiency drop off as you begin to exceed the number of physical cores.