Eh, not always plausible. I got it to work on a 2GB card, albeit very slowly, but that was apparently dumb luck.
Actually, it may have been some form of wizardry in the third-party drivers I was using, because now I've got a more powerful machine with a better card, and things are about as slow, but with weirdly more "out of memory" errors.
AMD vs Nvidia? AMD requires a lot of maneuvering to get it to work since AMD hasn't really moved to support AI image generation. I have an old Radeon 570 and a newer 6750xt that can work, but its all about setup.