I am on Windows, automatic1111 with directML and rendering is pretty fast. 7700x, 6750xt and 32GB at 4800mhz and a couple of m.2 drives. No xformers tho and some problems when upscaling in txt2image, but it renders prompts with default settings in 10 to 15 seconds. Fast enough for me. AMD has updated their Adrenalin drivers lately to have better directML performance.
Some things can take some time or aren't supported on AMD, but it's surely faster then my rtx 1070 and 1080 rigs wich performed adequately, except with training.