Overhead performance, so they mean things like OS, keeping track off your friend-list, the Snap function? As all of that is overhead for the game, and it makes sense that that performance is better with the PS4 seeing how the machine has a smaller OS footprint than the XbOne. This for instance can be seen in the CPU comparison chart from the Substance engine. Here it is quite clear that the CPU just has more to do with the Xbox One's operating system(s) than the one running on the PS4.
Now this of course will be turned into a Fanboy slug fest by Sony Pony's and XBots. After all to them it feels like they actually stormed the beaches of Normandy, had to be in pride marches to stay safe from bashers and lynchers (while still using the N word and several gay slurs as insults themselves on a regular basis) and feel more persecuted than the combined feeling of every downtrodden minority in this wonderful and splendorous decorated blue marble we call our home (I keep saying guys, God is one of us on the Fab side of the force
).
They will also not fully know what "overhead" means, and will just go with percentages, posting GIFS of Antonio Banderas (cute guy, but I doubt they post them for that reason) and being general nuisances. In fact most will now state that the PS4 is twice as powerful as the XbOne, will post several Cerny Gifs or Cloud images and scream "Have you seen Titanfall" and "Dat Balance".
When really it seems he is mostly talking about the general overhead the systems have. I really am not saying one is better than the other, I couldn't care less really seeing how I rather just invest in my Wii U, but it is just bugging me that these fanboys keep taking specs and stats wrong like this while calling it "math". It feels a bit like these people are trying to do my job and insulting me while at it. Yes the PS4 looks like a better gaming system if you look at the raw specs, but one doesn't just compare percentages indicating the amount of ROPS each GPU has and says one is twice as powerful as the other. There is a bit more to it than that.
Although I do agree that MS's APU is a very fill rate limited silicon, and maybe should have gone for a 32ROP set up as well. But I cannot look into their internal documentation, maybe they did the design and it really is a thing Developers just have to come to terms with.
Sorry for my rant, and I hope I haven't turned anybody off of playing his PS4 or XbOne. Just have some fun with your games and I'll do it as well with my magical plastic Wonderbox filled with magical entrails of plastic, gold, silicon and wires
.