@mpg1
Not sure if you were around when we were looking into specific XBO customizations. But moving from 720p to 900p for Xbox is pretty massive, which meant that they needed to leverage a feature that DICE wasn't using before.
So it's entirely possible that DICE are using that feature now.
tldr; it could be the move to DX12 and leveraging ExecuteIndirect Feature combined with the customized XBO Command Processor.
link to that discussion here on B3D:
#1804
ExecuteIndirect as well as some other features on DX12 have been known to improve performance, EI seems to be the big one in particular (my understanding on certain code seeing upwards to 15-20% improvement IIRC, will need to dive back into the DX12 thread). We have no known understanding of the degree of improvement on performance the microcode on the XBO Command processor has. But DICE seems very enthusiastic about it with their presentation. (perhaps another 10-15% on top of that and you are getting close to meeting 900p.)
It's perhaps, the only _true_ secret sauce that XBO has over any other hardware out there that we know of today. I expect that feature to make it back into AMD graphics cards, and of course we should see it for Scorpio.
I'm not sure if it makes sense to make a hoopla about it, it's also the most hidden and guarded secret of xbox, and it took nearly forever to find out about it. Luckily DICE made a presentation about EI or we would never have known it existed in the first place. We knew they made customizations to the command processor, we just didn't know what for. We've gotten really used to just seeing a 30% performance advantage on PS4 which is almost always translated into resolution; I suspect the resolution for BF1 will be 1080p on PS4.