"Our contacts have told us that memory reads on PS4 are 40-50 per cent quicker than Xbox One, and its ALU (Arithmetic Logic Unit) is around 50 per cent faster," Edge claims. A specific example suggested that without optimization, a platform-agnostic dev build can run "at around 30FPS in 1920×1080 on PS4, but it'll run at "20-something" FPS in 1600×900 on Xbox One."
One developer flat out said, "Xbox One is weaker and it's a pain to use its ESRAM."
Ouch. It's been widely speculated that the PS4 is more powerful than the Xbox One, though Microsoft has aggressively refuted statements like the one above. Just the other day Microsoft director of product planning Albert Penello took to NeoGAF to clarify the recent power comparisons, saying most are a result of "mis-information" about the Xbox One.
What's interesting, or perhaps terrifying, is that one source suggested "enforcing parity across consoles could become a political issue between platform holders, developers and publishers."
"They said that it could damage perceptions of a cross platform title, not to mention Xbox One, if the PS4 version shipped with an obviously superior resolution and framerate; better to "castrate" the PS4 version and release near-identical games to avoid ruffling any feathers."
That notion gets countered by another developer in the very next sentence, though.
The point of all of this? We need to wait until the PS4 and Xbox One actually release until we start making bold claims like "Xbox One is weaker." Until then, everything is strictly rumor and personal belief.