Source: http://www.theverge.com/2013/11/29/51273...

If the graphics upgrades between the two console generations fail to impress you, the distinction between the visuals on the Xbox One and PlayStation 4 will seem downright miniscule. For this first batch of launch games, however, Sony’s console undoubtedly has the upper hand. Across the multi-platform titles, the improvement comes down to one factor: higher resolutions. In the early running, most developers have been more successful at running 1080p at reasonable frame rates on the PlayStation 4 than on the Xbox One.Assassin’s Creed 4: Black Flag and Call of Duty: Ghosts, for example, run at 1080p on Sony’s console versus 900p and 720p, respectively, on the Xbox One. Battlefield 4, meanwhile, runs at 900p on the PlayStation 4 compared to 720p on the Xbox One.

In direct comparison, this resolution gap manifests itself with blurrier and more pixelated environments on Microsoft’s console.