Gamebrink has a video of an old PSP and one of the new slim PSPs to show you the difference in performance.
Both PlayStation Portables in this video load the game Final Fantasy Crisis Core. On the left is the old PSP and on the right the new PSP:
As you can see the new slim PSP is definitely a lot faster, at least in this game.
Sony PSP Slim much faster - video proof
Posted on Tuesday, September 18 2007 @ 2:00 CEST by Thomas De Maesschalck