The Evil Within was borderline unplayable before the day one patch
The Evil Within is not the smoothest-running game on any system, PlayStation 4 included. It was, however, running much worse than that prior to applying the day one patch.
Digital Foundry did a follow-up to its initial analysis of The Evil Within, which was based on the digital PSN version that comes with the day one patch (patch 1.01) included.
They decided to throw in the disc version and test it prior to applying the 1.01 patch and the results are nothing short of fascinating when you consider the game's dated look and the fact that it's based on the id Tech 5 engine - an engine that was designed to sacrifice everything for solid 60 fames-per-second gameplay.
In the video below, Digital Foundry puts the two versions side by side and shows us just how much better the day one patch makes the game.
There's a lot more insight into the initial resolution, frame-rate, how the term 'gold master' no longer means anything through the link.