Among the 300 odd fixes promised by Assassin's Creed Unity's third patch were a few to address framerate issues. Digital Foundry had a look to see what changes, if any, that's had. The short answer is it's made very little difference. Although, in all fairness, Ubi is promising another patch specifically to "further address framerate concerns."
You can see the video below, where Digital Foundry's Richard Leadbetter states, "we don't consider this a game changing update." The fix addressed these specific framerate issues:
- Improved general frame-rate on PS4 by lowering the priority of the online services thread
- Fixed FPS drops while Arno climbs on the RHP building of Palais de Justice
- Fixed FPS drops when in climbing and pressing the Left Stick towards somewhere that is not climbable in certain areas
- Fixed FPS drops in Sainte Chapelle
Leadbetter's conclusion, however, is that whatever improvements it's made, the effects are negligible:
The results? While we fully believe that Assassin's Creed Unity sees certain boosts to performance in specific scenarios, what's clear is that overall frame-rates only see a small improvement overall across the run of play. In our clips this amounts to a 1.95 per cent boost in single-player (25.07fps average vs the pre-patch 24.59fps) and only 1.6 per cent in co-op (24.29fps vs 23.90fps). As gameplay isn't absolutely matched, we consider this to be within the margin of error.