There are several companies like Dell and their U2913WM model, LG U2913WM, and the Asus MX299Q which support a 21:9 widescreen ratio. All have resolution size of 2560x1080. I know some games displays just fine with this unique ratio while others don't and have their HUDs being smashed in the middle. Would like to see an option to select the 21:9 ratio in the options menu.
Asus MX299Q:
https://www.youtube.com/watch?v=ug0-vkQiEcI
LG U2913WM:
https://www.youtube.com/watch?v=ZYHyH2pb2fk or this example https://www.youtube.com/watch?v=pTDBd8-Ubgo
Dell U2913WM:
https://www.youtube.com/watch?v=nYJtdImPrs
https://www.youtube.com/watch?v=Rf7FcIgkgDY