We used the full retail version of Quake 4, the fourth game in the Quake series, based on the technically sound Doom 3 engine. However, unlike Doom 3, we found that the game benefits from at least 2x Anti-Aliasing, and the experience with Anti-Aliasing at a slightly lower resolution was better than increasing the resolution with no AA applied.
Both Anti-Aliasing and Anisotropic Filtering were controlled from inside the game. When you select "High Quality" mode, 4xAF is automatically enabled, and when the "Ultra Quality" mode is enabled, 8xAF is automatically applied to the scene.
We did a manual run through from a five minute section of the Nexus Hub Tunnels level and found that a minimum of 15 frames per second and an average of 45 frames per second in our test section was deemed to be playable across the rest of the title.
Much like Doom 3, Quake 4 has an Ultra Quality mode that requires 512MB of video memory in order to store the sizeable textures used at this setting. We tried to play the game in Ultra Quality mode, but found that the highest playable settings we could achieve in Ultra Quality were 1600x1200 0xAA 8xAF. That gave us a frame rate of 19 fps minimum and 43 fps average.
We then tested the game in High Quality mode, and found that 1600x1200 2xQA AA 4xAF was very playable, and was not as choppy as our manual run through using Ultra Quality mode. On the whole, we felt that 1600x1200 2xQA AA 4xAF delivered a better experience, both in terms of the frame rate and image quality delivered. Anti-Aliasing helped to improve the gaming experience more than the higher quality setting, as there are very small differences between High Quality and Ultra Quality modes.
The XFX GeForce 7800 GTX delivered a much smoother gaming experience than the Radeon X1800XT at the same settings, with higher average and minimum frame rates along with a generally smoother looking frame rate graph. In contrast, we found that the reference GeForce 7800 GTX was noticeably slower than the Radeon X1800XT. We were not able to turn on either of the Transparency Anti-Aliasing modes, and had to settle with 1600x1200 2xAA 4xAF High Quality as the highest playable settings. That is not to say that the reference GeForce 7800 GTX did not deliver a good gaming experience - the two faster cards just delivered a better one.