Quantum Break is a unique blend of action-adventure game and live-action show where you play as Jack Joyce, who gains time manipulation powers after a failed time travel experiment.
Increase the VRAM to 5GB you can learn how to do that here.
This is important, Launch the game first and put the game to Fullscreen mode and 720p resolution. Exit the game and open up the command center and turn on AMD RSR.
Playing Quantum Break with my settings at 900p 20W gave me an average 50 to 60+ FPS on the ROG Ally. If you want better visuals you can play at 1080p 25W and average 40-60+ FPS.