In the single-player mode, the game runs at full 1080p with an unlocked frame-rate (though a 30fps cap has been introduced as an option in a recent patch), but it's a different story altogether with multiplayer. Here Guerrilla Games has opted for a 960x1080 framebuffer, in pursuit of a 60fps refresh. Across a range of clips, we see the game handing in a 50fps average on multiplayer. It makes a palpable difference, but it's probably not the sort of boost you might expect from halving fill-rate.
Now, there are some mitigating factors here. Shadow Fall uses a horizontal interlace, with every other column of pixels generated using a temporal upscale - in effect, information from previously rendered frames is used to plug the gaps. The fact that few have actually noticed that any upscale at all is in place speaks to its quality, and we can almost certainly assume that this effect is not cheap from a computational perspective. However, at the same time it also confirms that a massive reduction in fill-rate isn't a guaranteed dead cert for hitting 60fps. Indeed, Shadow Fall multiplayer has a noticeably variable frame-rate - even though the fill-rate gain and the temporal upscale are likely to give back and take away fixed amounts of GPU time. Whatever is stopping Killzone from reaching 60fps isn't down to pixel fill-rate, and based on what we learned from our trip to Amsterdam last year, we're pretty confident it's not the CPU in this case either.
http://www.eurogamer.net/articles/digitalfoundry-2014-in-theory-1080p30-or-720p60
