>> Has anyone had any success replacing a 1ghz logic board with a 1.2 ghz >> logic board in an ibook G4? I'd wager the performance benefit this would confer would not be worth the effort. You'd be looking at sometihng like a 5% speed boost, at a guess. If you have a spare logic board, chuck it in a custom case, and make a desktop with it, retining your current 1GHz iBook. my 2c, -Gus