In complex GPU-bound tests, such as a walk around the bustling Diamond City, we also see a divide in performance between the two consoles. Though most locations hold mostly steady at 30fps, this is one of the more densely packed, detailed spots in the game in terms of overall NPC count and geometry layout. As a result, both PS4 and Xbox One are prone to drops when walking around its centre, and Sony's machine consistently gives us the smoother return. On overlooking the city as a whole, Xbox One lags behind at a sustained 25fps in this case, while PS4 delivers at 28fps until we leave the scene. There's no question in this sense that PS4 leverages its raw hardware advantage into a performance lead - despite resolutions and assets being identical with Microsoft's platform.
It's a clear result across city areas, but surprisingly PS4 has a shortcoming elsewhere. While most battles produce a similar overall frame-rate, shootouts involving heavy transparency effects can affect PS4 more negatively than we'd expect. In extreme cases, such as on approaching an early Deathclaw enemy in Concord town, PS4 wavers close to the 20fps line when letting rip on a minigun. Fire, smoke, and blood splatter effects collide, and on re-testing this section several times on both consoles, Xbox One consistently produces a near-unshakable 30fps. It's possible this is a side-effect of Bethesda's choice to begin engine optimisations on Xbox One - but even so, PS4's lengthy stretches at the low 20fps range are out of place, given its advantages in every other area.
Indeed, just about every other battle produces similar results between the two consoles. Tackling a zombie swarm in a later city area, for example, PS4's frame-rate doesn't struggle noticeably when compared to Xbox One - and drops appear from both sides. It suggests it's only a problem in extreme cases, where effects are used to excess. On balance though, PS4 is in the better shape as terms of consistency across the game; it has nothing close to the stuttering seen on Xbox One, and a better frame-rate in big towns and cities as well. Xbox One has a repeatable advantage in the Deathclaw battle, where effects clash heavily, but in most scenarios we get matching, or superior results on PS4.