NVIDIA GeForce FX 5800 Ultra: It's Here, but is it Good?

Anti-Aliasing Performance

With the image quality investigation over with, now it's time to look at the performance of all of these AA settings. As usual, the newcomer goes first - let's see how the GeForce FX's performance is impacted by its plethora of AA settings:

Impact of Anti-Aliasing on Performance NVIDIA GeForce FX 5800 Ultra Anti-Aliasing Off 2X QC 4X 6XS 8XS 100% 90% 90% 76% 39% 31% | 0 | 20 | 40 | 60 | 80 | 100 | 120

Just as NVIDIA has promised, both 2X and Quincunx modes are virtually "free" but as we all know, just because something is "free" doesn't mean it's good. Flip back a page to our comparison screenshots and you'll see that neither of these modes does much in the way of actually anti-aliasing, so we turn to some of the higher sampling methods.

Next up we have NVIDIA's 4X mode, which delivers around 3/4 the performance of the FX 5800 Ultra without any sort of AA enabled. As you can see, once you get beyond 4-samples you're reducing the performance of the card to less than 40% of its original capabilities.

Once again we look at the lower clocked GeForce FX 5800 to see how having less memory bandwidth and a lower fill rate influences performance:

Impact of Anti-Aliasing on Performance NVIDIA GeForce FX 5800 Anti-Aliasing Off 2X QC 4X 6XS 8XS 100 84 84 66 33 22 | 0 | 20 | 40 | 60 | 80 | 100 | 120

The performance drops are much more pronounced on the regular 5800 as you can expect given the 20% reduction in core and memory clocks.

Impact of Anti-Aliasing on Performance ATI Radeon 9700 Pro Anti-Aliasing Off 2X 4X 6X 100% 82% 70% 60% | 0 | 20 | 40 | 60 | 80 | 100 | 120

With the Radeon 9700 Pro we see that both the 2X and 4X modes take a slightly larger performance hit than the comparable settings on the GeForce FX, but what's truly interesting is ATI's 6X mode. A feature that ATI hasn't done a great job of publicizing is their frame buffer compression algorithm that is enabled only in AA modes, but it does boast a higher compression ratio than NVIDIA's 4:1 color compression algorithm. The benefit of this higher ratio compression algorithm can be seen in the relative performance of ATI's 6X AA setting, it delivers 60% of the 9700 Pro's original performance compared to the GeForce FX's 6XS mode with its 39%.

If you want numbers to quantify this difference, with 4X AA enabled the GeForce FX 5800 Ultra is around 9% faster at 1024x768 than the Radeon 9700 Pro (156.9 vs. 143.8), but switching on 6X AA puts the 9700 on top of the FX by no less than 53% (123 vs 80).