Note that the Geforce 6800 GT and Geforce 7950 GT run with the image quality set at Low (1280, 1680, 1920 pixels) and at Medium (1280 pixels), whereas the Geforce 8 and 9 were tested at High (1280, 1680, 1920 pixels) and Very High (1280 pixels). These settings are necessary for the older graphics card to be in a position to send a playable number of frames to the monitor. These differences mean that sometimes a weaker graphics chip can move up to a higher position in the rankings than a more powerful Geforce 8 or 9. The better frame rate is, in these cases, only achieved by reducing the image quality.
The Geforce 6800 GT does not react to increased CPU power. The Geforce 7950 GT needs at least 2.67 to 3.0 GHz, or more CPU cache, in order for the graphics performance to be fully exploited. The Geforce 6 and 7 only run with DirectX 9, which doesn’t make much difference as the graphics quality is set to Low; this means that there are few effects where you would actually see a difference.
The Geforce 9600 GT compares favorably with the more powerful Geforce 8 and 9. A CPU basic level of 2.67 GHz or a quad core processor should be used. The new G92 graphics cards cooperate much better when they have sufficient clocking rates available. Overclocking the CPU ekes out a couple of extra frames for the Geforce 8800 and Geforce 9800 GTX.