Quake III is very dependant on fillrate for smooth game play, so anyone with a GeForce2 should remain happy, despite the CPU. No matter how powerful your processor is, if you are still running a Rage Pro, this will definitely not be your favorite game.
We benchmarked our Value systems against our Performance machines in order to get a good idea of how the individual platform affects frame rates. Desktop color is set to 16-bits in order to ensure all tests run at Normal Quality indeed defaulted to 16-bit. All timedemos are run with the sound system "on," because that's the way the game should be played.
The Celeron system doesn't provide enough power for the GeForce2 to become heavily weighed down. Conversely, the Performance machine feels a fillrate limitation closer to 1280x1024.