Without the patch, Assassin's Creed 4 will render at 900p and be upscaled to 1080p resolution on PS4. Ubisoft communications manager Gary Steinman explains why there's a discrepancy between the game that shipped and the title update Ubisoft is rolling out after launch.
"[It was to] meet an essential goal: deliver a visually brilliant game at a steady 30 frames per second (the industry gold standard for open-world games)," Steinman said. "Finishing the game at 900p gave the development team the extra room in terms of the GPU and CPU usage to ensure the framerate never dips below 30 frames per second. The team then used the time between the ship date and the release to focus on a title update that could deliver native 1080p resolution on the PS4."
The title update will also bring with it "a brand-new anti-aliasing technique" to further improve the PS4 game's visuals, according to the post, a feature that will also apply to the Xbox One version shipping next week.
Developer Infinity Ward issued a similar update to the PS4 version of Call of Duty: Ghosts to bring the game's single-player campaign up to 1080p resolution. Publisher Activision said the resolution difference was due to a "configuration error" in the retail disc version.
Assassin's Creed 4: Black Flag is available for PS4 today. Read Polygon's review of that version and the previous console generation versions for our thoughts.