On my 3,440 x 1440 monitor, the software recommended I use an in-game resolution of 2,560 x 1,440 to get the best experience, however, you can specify the in-game resolution.

AMD Radeon Super Resolution is a driver-based image upscaling technology compatible with innumerable games. To enable RSR, all you'll need to do is flip a switch in the Adrenalin software.