Yeah, a lot of games (mostly exclusives) will be able to use 100% of the power on any given console, but like he said, their are always ways to be more efficient. Sony's last 2 consoles have been relatively difficult to program for and developers need time to figure out how to make proper use of the architecture. This is why we see such vast improvements as the generation progresses.
Just compare the late PS2 games to the early gen games.








