I’ve since got a newer graphics card myself since this post. Processing is similar with OpenCL turned on, including those mentioned in the article above. I’ve tried with 2.10.6, and 2.10.7 and 2.99 from git. Despite now having a good OpenCL stack, nothing seems to run on the card. I have a rx560 now, and can run OpenCL benchmarks without issues. So I’m a bit stumped. It really looks like OpenCL is not working for GEGL operations. I’ve used ‘radeontop’ to see if there is any action going on on the card, there isn’t. It’s time to ask the developers I think.