I want technical answers to this, not simple answers, because the are too many articles on the web that don't really answer my question. I want to understand specifically why consoles have better frame rates, less stutter, and less volatility in frame rates than pc for all their games. I want to specifically compare the xbox360 to pc, I consider both the Xbox and ps3 similar. I used to have an Xbox360, and I noticed that the game frame rate performance was optimal and I didn't notice any stutter compared to a pc with a better graphics card than the Xbox ATI Xenos of the Xbox 360. But I don't understand how a console with an old ATI Xenos is capable of playing the latest games like battlefield 3 with good average frame rate performance.
Some of the reasons that I think help the Xbox 360/ps3 keep a good non volatile frame rate is because the games are obviously optimised better for it's operating system, and it's hardware. System resources are used less for background tasks and transferred more efficiently for games, and the graphics are slightly inferior to pc. But I don't understand how these few reasons allow the Xbox 360 to maintain such a good and stable frame rate compared to the pc. Another thing I get the impression of is that the Xbox and ps3, might have a free form of antialiasing like Fxaa, that is optimised for polygons and 3d images so it doesn't effect the text. I noticed that turning aa off for games on the pc will substantially increase performance, but I don't understand how a massive difference in hardware from an ATI Xenos, and say an ATI 4670 (I don't have this card anymore) still sees that the ATI Xenos is still reaping much higher performance even in the latest games. When I play on the Xbox I feel like the FPS is near 60, so don't tell me that it is playing at 30 which is why it is less volatile than pc frame rate.
Also take into account that the pc variables I'm comparing to the Xbox is one with no background applications or tasks using system resources other than the game itself, and a pc with a good (but older) graphics card and CPU for gaming.