Just remember that the higher your clock frequencies the more juice it will need, too—you'll kill your batteries quickly unless you're plugged into a wall socket or power strip. Also, considering the tight confines of a laptop case, overheating can be an issue, so I would only use the stock settings and any "turbo mode" feature it may have, like JJ said.
If you have space for a desktop and don't need to take your gaming rig everywhere with you like some kind of glorified GameBoy, though, you should really look into one of those instead as it's more powerful and economical. But it's not always practical for some people.
