Like daskrabble said, this highly depends on the game you're playing but also the resolution you play at. I have a q6600 @3Ghz with a 4870 and play at 1680x 1050. When I played a lower graphics game like WoW, the fps was negligible between the stock clock and 3Ghz. However, when I played Fallout 3, the difference between 2.4Ghz and 3Ghz was huge. There wasn't much of a difference inside buildings but whenever I went out to the Wastes(the open area) it lagged like crazy at 2.4Ghz but while at barely stutters at 3.0Ghz. I'd imagine it would be even better at 3.2Ghz but I haven't been successful at OCing it even to 3.1Ghz with my old chipset.
So, if you are going to be playing any recent games, I would have to say that answer is definitely closer to "no" than "yes".