We tested by setting Quake 4 to high quality, and then changing to the desired resolution with AA off. Here we see the 6800GT drops off noticeably at a resolution higher than 1024X768. The 7800GTX stays North of 60fps at each resolution, and the 7800GT SLI setup is able to pass it by about 10% at 1600X1200. Solo the 7800GT hangs pretty well with the 7800GTX. The X800XL 512MB drops off considerably after 1024X768 and really is not in the same league as the GeForce cards. At least the extra memory allows it to keep up with the X850XT PE which can not hang with the 6800GT. Now lets see how performance fairs when we switch to 4XAA.

As the results show, upgrading to one of the fastest consumer CPUs isn't the way to go to crank more performance if you already have a mainstream class CPU like the AMD Athlon 64 3500+. Given the 12% performance boost at low and mid-range resolutions and none at the high resolutions, the extra investment to obtain an FX-55 class CPU isn't too justifiable. Hence for Quake 4, the more worthwhile solution to crank high-resolution performance is naturally the SLI path to double your graphics crunching power (or the CrossFire route if you are using ATI's graphics cards).