When run through our benchmarks the R9 Fury X shines at 4K resolution, almost matching GTX 980 Ti, with just 3% difference. NVIDIA's GTX Titan X is still 8% ahead, but the performance is extremely game dependent. Most of our titles have the Fury X head to head with NVIDIA's offerings, sometimes slightly ahead, but then there are some games where the Radeon falls behind a lot. If we cherry pick and exclude Project Cars or World of Warcraft, then Fury X almost exactly matches GTX 980 Ti - at 4K, but consider that the next game that comes out and that you want to play might have similar troubles.
As soon as we start looking at lower resolutions, the performance gap suddenly widens. 4K, vs. GTX 980 Ti: -2%, 1440p: -9%, 1080p: -14%, 900p: -18%. This means that for anything below 4K gaming, which includes 1440p, the Fury X can not compete with NVIDIA's offerings. So if you are thinking about 144 Hz 1080p gaming, then GTX 980 Ti is the way to go now. For 4K gaming the Fury is good though, and it looks like AMD's driver team has gotten more active, too, a driver for Batman: Arkham Knight was released shortly after the game's launch, a welcome improvement that will hopefully last.