Hi,
I've a suggestion for the speed up of ATK for the future releases. We've used an electromagnetic software and the provider offered an acceleration option using the specially designed cards using GPU (Graphical Processing Unit) for FDTD calculations. The link is as follows for the accelerator cards:
http://www.remcom.com/xf7/xstream . I do not know what happens exactly inside the ATK motor (I know very complex thing occur

), but I thought ATK may use an accelerator solution.
Cheers,
Serhan