Uh, not sure? I downloaded the portable build of ComfyUI and ran the CUDA-specific batch file it comes with.
(I'm not used to using Windows and I don't know how to do anything complicated on that OS. Unfortunately, the computer with the big GPU also runs Windows.)
Haha, I know how it goes. Thanks, I'll give that a try!
Update: works great and much faster via ComfyUI + the provided workflow file.