According to Sony, developers make very little effort to enable enhancements like 1080p 60FPS or super-sampled graphics in old PS4 games on the new PlayStation 4 Pro.
One of the biggest selling points of Sony's new 4K-ready PlayStation 4 Pro is that it's fully backward compatible with all existing PS4 games, and can even provide performance and graphical boosts for current PS4 titles with Forward Compatibility updates. We had originally worried that these Forward Compatibility upgrades would possibly quite an involved process, but Sony says that it's incredibly easy and only takes "a fraction of a percent" of the original game's development efforts.
"The target was to make sure that support [for the PS4 Pro] could be done for a fraction of a percent of the overall effort," PS4 Pro architect Mark Cerny said in a recent interview with GamesIndustry Biz. "And I do mean a fraction of a percent. I mean, I've run the math, and it's 0.2 or 0.3 percent for these projects -- some of them. So at that point, I think it's very natural for the development community to support the platform."