While we found the Guillemot 3D Prophet to be very stable at its default clock settings, we did also manage to overclock it by a little over 8% on the core speed and almost 5.5% on the memory clock. At higher settings the image was corrupted and the applications crashed.
(For instructions on how to overclock your 3D Prophet, go to our GeForce DDR Guide overlocking page. But don't tell anyone we said you could do it.)
Results were mixed. On Quake 2 at lower resolutions (640 x 480 and 800 x 600), the scores were affected by 18% to 33% of the core speed increase and 28% to 50% of the memory. At the higher resolutions (1024 x 768 and 1600 x 1200), the increase rate jumped. 87% to 92% of core and 134% to 142% of memory speed increases were observed in the actual scores. This jump in the rate of fps gain as a percentage of overclocking shows that the extra MHz gained from overclocking have a much greater impact on performance as resolution increases. However, the highest raw increase was almost 9 fps achieved at 1024 x 768.
At the lowest resolution, a slight decrease in performance was noted over incremental overclocking adjustments indicating that, as the maximum overclocking speed is approached, there is a measurable negative effect on performance at lower resolutions. This may be a good way to minimize the possibility of damage while overclocking. By observing the scores at 640 x 480 as the clock speed is increased, any decrease in performance over previous increment may be a pre-curser to failure. This was also observed in the Quake 3 scores.