It was discovered that Horizon Zero Dawn would be getting a Day One Patch to help boost the performance of the game for both PS4 and PS4 Pro users. This patch has gone LIVE for those lucky enough to already have a copy of the much-hyped PS4 exclusive. The details straight from the 227mb update:
The ‘updated visual settings’ includes two new modes for PS4 Pro users. A ‘favor performance’ focuses on making framerate smooth and stable, while the ‘favor resoltion’ pushes the game to 2160P. Which will you use?