SLI is supposed to get around a 100% performance increase, right? But looking at benchmarks, I've realized that video cards with faster RAM access would have an easier time with games that rely on textures more for graphics, as opposed to polygons and floating points etc. With SLI, texture information is the same in the RAM when using Alternate Frame Rendering, and with Split Frame Rendering, one card does half the screen, and the other does the other half of the screen. Therefore, with games like Doom3 that have no texture compression at max settings, for example, would be better with Split Frame Rendering. Other games that have smaller textures, or use better texture compression would have higher framerates with Alternate Frame Rendering.

I also would guess that with video cards would have higher frame rates when the memory clock speed is overclocked, and react better with AA and AF, or with higher resolutions, with an overclocked core speed. I haven't been able to test my theory, since my monitor's highest res. is only 1280x1024, and I get a headache with 800x600.