No gaming console has ever launched with a CPU even close to comparing to the better PC processors at the time of launch. They win by offering additional stuff you don't find on the average PC... new GPUs, extra processors as on the PS3, etc. The PPCs in the PS3 and X-Box 360 were clocked very fast, sure, but they were super simple processors, simple pipeline, small caches, etc. compared to desktop processors.
It's easy to understand why. For one, a game console has to be relative cheap to sell. They come out expensive, early on, to help cover the NRE on the design, but they have to be able to get cheap... no one wants to subsidize the cost for the life of the product. They also have to be low power.. no one will accept a huge fan in their livingroom. So the design has to be largely something that can be integrated onto a few chips.
Both PS4 and X-Box One are using multi-core AMDs, both with an upgraded GPU architecture. These are not going to outperform my desktop PC. On the other hand, being on the same chip, the CPU to GPU path is faster than any PC (well, other than those new ones using the same tech that's been released into new AMD chips), and yet it's not the crap GPU you find in, say, Intel's laptop processors.
And then the other factor in gaming consoles... the games get optimized for that specific architecture. Gaming companies know they have 5-8 years of the same console, with virtually no piracy. So they put in the time to optimize for a specific console. Every PC has different CPU and GPU combinations, so there's never this kind of machine-specific tweaking for PC gaming. Sure, new games will look better on your best-in-class PCs. The consoles always look better than mainstream PCs, at least for a couple of years.
