Sony's PlayStation 4 Pro (launching in November) and Microsoft's Xbox One Scorpio (launching late next year) are giving the pixel-counters out there a new, 4K-sized battlefield to fight over. Now, Microsoft is drawing a line in the sand in that developing battle, with Microsoft Studios Publishing General Manager Shannon Loftis telling USA Today that "any games we're making that we're launching in the Scorpio time frame, we're making sure they can natively render at 4K."
The word "natively" is important there, because there has been a lot of wiggle room when it comes to talking about what constitutes a truly "4K" game these days. For instance, according to developers Ars has talked to, many if not most games designed for the PS4 Pro will be rendered with an internal framebuffer that's larger than that for a 1080p game, but significantly smaller than the full 3840×2160 pixels on a 4K screen (the exact resolution for any PS4 Pro game will depend largely on how the developer prioritizes the frame rate and the level of detail in the scene). While the PS4 Pro can and does output a full 4K signal, it seems that only games with exceedingly simple graphics will be able to render at that resolution natively.
Sony says the PS4 Pro's internal rendering pipeline and some proprietary upscaling techniques will improve lower resolution base signals to take fuller advantage of a 4K display. But no amount of upscaling can fill in those missing 4K pixels as well as hardware (and a game engine) that natively generates images at full 4K resolution—or so the argument goes.