Just to give an idea of the speed up from going from processing individual arrays to batch processing - an Image I was rendering went from 2 hours to 20 seconds

Just to give an idea of the speed up from going from processing individual arrays to batch processing - an Image I was rendering went from 2 hours to 20 seconds (and that was with further obvious speed ups left on the table as well). Oh, and make sure you're using 64-bit version of python as you'll be slinging multi-gigabyte arrays around all over the place.