Bay Trail Atom is the equivalent if your comparing just the CPU. It's basically a modified version of their mobile APU. The Ps4 runs at like 1.6 ghz 8 cores while the Xbox One is 1.75 ghz, there is also a Arm chip in there that handles the OS.
The claim on the Emulators is CPU: With 2 cores 3.0GHz or better, RAM: 3GB, HD 7870 but I doubt that. I would imagine with the coding a I7 Overclocked and a 760 would be more playable.