In order to explore CPU scaling, I used the overclocked GeForce GTX Titan on multiple platforms and the Ultra detail preset at 1080p.
Intel and, to a lesser extent, AMD will like this: even pushing the Ultra detail preset, Watch Dogs is a CPU-bound game. Ubisoft Montreal developed the PC version in concert with its console efforts, and optimizations for those platforms seems apparent. Programming for the PlayStation's and Xbox's host processors involves getting the most out of fairly lightweight platforms. Naturally, then, well-threaded desktop CPUs benefit strongly.
When it comes to gaming, we rarely see the FX-8350 outperform a Core i3. But AMD's flagship walks away with a clear win in that match-up. Based on what we're seeing, serious fans of the game will want an FX-6000-series chip at least, but an FX-8000 or Core i5 should be much better.
Low-end CPUs suffer most, as we'd expect, when frame time variance is measured. Both the FX-8350 and Core i7 exhibit a couple of spikes too, but they demonstrate much less variance on average.