Here is an interesting slide from AMDs product roadmap. They were expecting performance increase of 10-15% with Piledriver. And that is what they got... but thanks to the fact their manufacturing process is more efficient they managed to push 10% extra clock speed for about 20% better performance.
Unfortunately intel also jumped around 10% with ivy bridge, without changing the clock speed at all. They can not catch up in core for core, clock for clock performance at all.
Looking at this graph and current trending performance increases, the only way AMD can catch in overall performance is if multithreaded performance becomes the norm for majority of programs, including games.
To present this mathematically, in terms of gaming performance best AMD can hope for is full 8 core support and scaling.
Intel - 1.5 + 1.5 + 1.5 + 1.5 = 6
AMD - 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 = 8
