Page 22 - Prey & Far Cry Coverage Sampling Antialiasing (CSAA)

Coverage Sampling Antialiasing (CSAA)

As you have been able to read there is a new very efficient AA mode available for the G80. It is called Coverage sampled antialiasing and will allow you to have 8 and 16x AA at the cost of roughly what you are used to 4xAA. The NVIDIA Control Panel now supports the following three antialiasing modes:

1. 1. a) Application Controlled AA is completely controlled by the in-game settings.
   2. b) Application Override AA is completely controlled by the NVIDIA Control Panel. In-game settings are ignored.
   3. c) Application Enhanced AA setting (i.e. 4x, 8x, 16x, etc) is determined by the NVIDIA Control Panel, but the application determines whether AA is on or off and what surfaces AA is applied to. This mode allows for applications to take advantage of the GeForce 8800 GPUs' new 8x and 16x AA in a more reliable, compatible manner than the Application Override mode. This is the recommended mode for all applications. Basically if the software can allow it it'll try to do Coverage Sampled AA.

We fired up a couple of games with 4xAA, 16xAA (Coverage Sampling) and 16xQAA with also 16x anisotropic filtering enabled with two applications, Prey and Far Cry. Have a look first at Prey:

So here we tested both the GTS and GTX cards with all common used resolutions. The charts are difficult to read, so please bare with me. Let's have a look at the GTS (the first three left results in the chart.

First we have 4xAA, which obviously would offer the best performance. The third result is 16x QAA, which quite frankly should hardly be even possible to render. But what I need you to do is focus on the 2nd from the left yellow bars. That's Coverage Sampling AA at work. Now what you need to understand is that we are rendering the game at 16x AA here, that 16 samples. Although it's definitely a tough nut and certain applications will take advantage of it more than others, this is definitely already impressive. The GTX for example at 2560x1600 (which is 5x more pixels than 1024x768!) is still playable with the game at the very best configurable image quality settings, and then 16xAF and 16xAA. Playable with 34 FPS on average. That's just staggering.

Traditional AA modes would have killed off the performance here to unplayable levels.

But I already stated that certain applications benefit more from CSAA than others, with that in mind, let's have a good look at far Cry.

As you can see and again focus on the yellow bars that's CSAA at work. We can play Far Cry with our heavily maxed out in-game IQ configuration, then enable 16 levels of anisotropic filtering and then enable 16x CSAA at 2560x1600 and are still able to pull a rabbit out of a hat, 45 FPS and the most breathtaking scene you've ever experienced.

As Borat would say... izze very nice!