Well I don't know what kind of insurance you have, but willful destruction usually isn't covered.... and that is pretty much what you would be doing to the PowerBook by overclocking it.
Plus, what Aptmunich said is not irrelevant. Yes, RAM does cost money, but not nearly as much as it would cost to try and repair a botched soldering job from a failed overclocking attempt.
It sounds like you, like many others here, seem to be fairly PC/Windows knowledgable...but what you are failing to realize is that those rules don't always apply in the Macintosh world.
Upping your system RAM will improve your framerate. Also, assuming you are running Tiger, something as simple as disabling Dashboard would show a slight increase in framerate.
Still, with all this focus and talk about framerate, I would be inclined to think that you are trying to improve gaming on your Mac. This really won't happen, as gaming always has been and likely always will be better on a Windows PC. Sure you can game on a Mac, but it will never be the same as gaming on Windows.
So in summary, if you want to have a better gaming experience, then use your Windows PC for it...don't ruin a Mac by trying to overclock it.
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