I've got a nVidia 1080 and it was choppy even after I dropped the quality lower than I liked. You can still use the modified exe from WSGF to get ultrawide, but much like Advanced3 noted, it's terrible. I'm eight months late to the conversation, but I've been playing Black Flag on my ultrawide 3440x1440 for an hour and thought I'd save the next person searching for this some time.
