And what does tesselation do?
Here are some quotes from HardOCP's Unigine Heaven Benchmark review:
http://www.hardocp.com/article/2009/11/06/unigine_heaven_benchmark_dx11_tessellation
"Enabling DX11 compared to DX10 was positive for performance. You can clearly see that DX11 is slightly faster than DX10 all things being equal. This is good news and gives us hope that DX11 wont suffer the huge drain on performance that DX10 did at the beginning of its short lifespan. There was a noticeable drain on performance enabling Tessellation however;
the extra polygons do eat up performance. The Benchmark was still above 30 FPS at this setting at least on the Radeon HD 5850 and Radeon HD 5870."
"These images are self explanatory; Tessellation has the ability to add a lot of detail.
What you see is that in the images without Tessellation there are fewer polygons, they are very simple and flat. When Tessellation is enabled the engine is dynamically generating in real-time more polygons as you move through the environment. This effect cannot be seen in these still screenshots, but if you run this program with the wireframe enabled and watch it in motion you will see the geometry being created on the fly.
Tessellation is quite amazing,
and it really does add detail. The dragon alone has so many polygons with Tessellation that it looks like a texture wrapping around it. I was also impressed how much better things like the rope look with Tessellation. The rope actually looks like a rope with Tessellation. This is just an insane amount of geometry, no wonder why there is a large performance drop. Obviously a developer might not want to use this much in-depth Tessellation since it causes a large performance drop."
Tesselation adds polygons. A lot of them. And if say for example an HD5870 and GTX470 are roughly equal without tesselation, then enabling it tanks the HD5870 far more than the GTX470, what does this tell you? It tells me that the huge polygon increase is handled better on the GTX470. This article also mentions that there are several games on the way utilizing this engine. Under NDA, they could not mention the titles.
Here is a snip from the Summary of the article:
"While this Heaven Benchmark application isnt an actual game, it does give us a glimpse of how Tessellation might be used in games. If used in this manner the benefits can be quite noticeable and greatly improve the gaming experience."
So, this actual engine will be used in games. And it's up to the developer as to actually how much tesselation is used. The more they use, I think you might know which cards may struggle more. You can say that the Unigine Heaven Bench is an extreme case of tesselation usage, but it gives an indication that when the geometry in cranked up and polygons severely increase, GTX4xx series has a leg up.
This is a feature. Much like any other. For example, in the past gens, AMD cards suffer less from higher levels of AA. Just the way it is.
Imagine an in-game setting that has a slider to control the level of tesselation, or just turn it on or off? Depends on dev I suppose.
Thoughts Dug? ZeroCool?