But after a long process of deduction, the actual answer is rather simple - and discernible in the opening area of the beta, as soon as control is handed over to the player. It's clear from this viewpoint that Xbox One utilises a dynamic resolution scaler in order to sustain its target frame-rate, much like Halo 5 and Wolfenstein: The New Order. Essentially, this means that the game adjusts its resolution on the fly, dependent on GPU load in any given scene.
So what exactly is the resolution? Well, the short answer is, it varies depending on the rendering scenario. In the opening shot, Xbox One drops to 1792x1008 as we look at the recovery camp ahead, as especially noticeably on a rooftop structure to its right side. This is still much higher than the 900p output we see in other titles, and it ultimately sits around 87 per cent of a full HD image overall. In other words, it isn't always a vast difference, but it's notable in explaining why we see certain details losing some definition.
As for PS4, it may be the case this scaling method is implemented on Sony's machine too. However, so far our tests reveal no performance drops whatsoever from the full 1920x1080 (or 30fps) so far, and we'll have to judge this point on the final release. Meanwhile we'd love to see this technology deployed on PC in some fashion, where our GTX 970 and R9 390 tests show gameplay frame-rates can vary dramatically. A dynamic resolution could be a good back-up solution for those struggling to get by on their current GPUs on high settings - and also for PS4, should there be any issues in maintaining 30fps later on.
https://www.youtube.com/watch?v=0cukClU246w
http://www.eurogamer.net/articles/d...sion-beta-on-xbox-one-uses-dynamic-resolution