[AmVess]

I don't know what the breakdown is (what number of cores goers to OS,number of cores for the games), the the Xbox One has a rather low performance 8-core AMD unit; the cores are provisioned amongst the OS and games as needed.

Since the CPU is low performance, the OS could easily eat 50% of its total performance, leaving scant little for games.

[ekianjo]

It'd be interesting to know the figures for the PS4 - whether the OS has a significant footprint or not when games are running. Is there any source for the PS4 available anywhere?