At launch, AC IV had been running at 900p resolution on PS4. Which looked perfectly nice, but wasn't the full 1080p resolution that a lot of other next-gen games can muster. Ubisoft had promised a patch that would bring the game's resolution up to 1080p, and this week they delivered.
Eurogamer's Digital Foundry has a nice breakdown of the patched version, along with the video up top, which compares the two. It's not that easy to tell the two apart in the video, but over in their article, they've got some screenshot comparisons that lay out the difference. I've played a good amount of the PS4 version pre-and post-patch, and I definitely noticed the difference upon firing up the patched version last night. It's subtle, but it's there. (Update: For those who want a detailed view, check out these GAF Gifs. Cheers, Korpse.)
Pleasantly, Digital Foundry reports that the increased detail comes with absolutely no decrease in performance—the game remains locked at 30fps. It's enough to make you wonder what the PS4 could handle if Ubisoft unlocked the framerate.
All this extremely focused technical stuff is a little bit granular, but I enjoy it—feels like the first small steps on the long road toward a thorough understanding of what these next-gen consoles are really capable of. Check out Digital Foundry's whole report for more.