the GTX 980 was doing 90 fps without 2 years of optimization while the PS4 is now doing 60fps. Now, they are extrapolating the 60fps to 120fps for VR. From the article:
"But now Showdown can run flawlessly at 60 FPS on Sony’s Morpheus headset for PS4, says J.J. Hoesing, Senior Engine Programmer on Epic’s VR Team. The demo of course takes advantage of Sony’s ‘asynchronous reprojection’ technique to ultimately output at 120 FPS."
Translation: Two eyes means two frames, so you get 120fps from 60fps. Right?