Now news hits the wire that Assassin's Creed Unity will run at sub-1080p resolutions on both consoles. Senior producer Vincent Pontbriand revealed the game will be limited to 1600 x 900 and 30fps "to avoid all the debates and stuff." Pontbriand says GPU horsepower isn't the limiting factor, he points to the CPU as the bottleneck, which he claims struggles to process the AI and the number of NPCs they have on screen.
Developer Ubisoft Montreal apparently didn't expect the CPU limitation. The team anticipated "a tenfold improvement over everything AI-wise," Pontbriand said, but they were "quickly bottlenecked." He describes the limitation as "frustrating" and says the game could be running at 100 FPS if it was "just graphics." Seems like this generation of consoles has enough pixel-pushing prowess for prettier visuals but not enough CPU power for richer gameplay.
The Xbone and PS4 are both based on custom silicon with eight x86-compatible CPU cores. That might sound potent, but those cores are derived from AMD's low-power Jaguar architecture, which is designed for mobile devices like cheap tablets and notebooks. Intel's eight-core Core i7-5960X processor is a whole other class of CPU. So is the dual-core Pentium G3258 Anniversary Edition, for that matter.