Thats just pixel count. You're doubling your geometry passes, quite possibly being forced to include more in each pass (most Halo games have larger FoV in split-screen), and even the per-pixel costs can be larger since GPUs generally carry out pixel shading in quads (less efficient for smaller polygons). Some of that can be mitigated with geometry LOD systems and such, but in general, split-screen tends to be more expensive than single-screen even if the raw pixel throughput is supposedly the same.You have to render half of the pixels for each screen. You still have 1x 1080p@60fps in splitscreen.
For similar reasons, 720p60 is usually harder to pull off than 1080p30, even though the latter represents a bit more pixel throughput.
Not in general, no.Meaning I was assuming that even if the single player 60fps campaign is squeezing out 100% of the XB1's power, then the game should still be able to pull off splitscreen 60fps.