Well, the Acer XB270H-G is only 1080p so for Triple A title games, it won't be difficult to run especially with a 980 Ti. In fact, a 980 Ti is a bit overkill for a 1080p panel even if it is 144 Hz. If you want, I'd suggest going for a 2k monitor at least. There's some great 2k 144Hz G-Sync panels for around the same price as the XB270H-G.
Newegg is having a sale on this Dell Monitor for $520: http://www.newegg.com/Product/Product.aspx?Item=N82E16824260333