Richard

@uhoh: I'm merely asking for what I think I need. Sometimes I code is useful to me, other times not. This isn't normative: if you don't want to post code you don't have to, but I think in this instance it limits my ability to help. In addition, if you've looked at my other answers, you'll already know I think arrayfire is a nice way to offload.

Seeing what your CPU-based code looks like, or an MWE thereof, would help me, at least, understand what you're doing. That, in turn, would help me make better suggestions.