For the lowest acceptable performance, we want the minimum frame rate at or above 30fps. The slowest graphics cards to achieve this include the Radeon HD 7870, 270X, RX 460 as well as the GeForce GTX 760 and 950.
For a smoother 40fps minimum, cards including the GTX 960, 680 and HD 7970 GHz, R9 280X and R9 285 will suffice at 1080p. Fortunately, most modern and even many old GPUs can push over 60fps at 1080p. Pretty much anything from the GTX 780 Ti and RX 470 up will provide a nice experience.
1440p Performance
Gears of War 4 is surprisingly hardware-friendly even at 1440p. Here the R9 380X and GTX 780 provided playable performance while the GTX 780 Ti and RX 470 delivered even smoother results. That said, for an average of 60fps gamers will still require a Fury or GTX 980 Ti.