The official GT300/Fermi Thread

[Florinmocanu]

I also agree with users worrying about no HW tesselation. Tesselation is one of the big or maybe the biggest feature of DX11, smoother surfaces, better models. I do not understand why they didn't implement DX11 at it's fullest.

It may bite them in the or not, we will have to wait for AvP to see what this lack in feature means.

It reminds me of FX 5800 vs Radeon 9700 Pro all over, when the FX series didn't support properly DX9, which was seen later when games like Oblivion came which required SM 2.0 and a lot of effects which could be enjoyed on the 9800/9700/9600/9500 series couldn't be enjoyed on the FX series without a serious performance hit.

[Farinorco]

But who said they are not implementing DX11 or tesselation at its fullest?

DX11, as an intermediate layer between hardware and applications, it's an interface than offers a certain functionality (with a given interface) in the side of the applications, and that asks the hardware to implement certain functionality (with a given interface) to be compliant with the API.

What the hardware does internally to execute (and resolve) that functionality, it's its own business, while it picks the right ins and gives the right outs.

The NV's decision of implementing tesselation completely as operations in the CUDA Processors instead of having dedicated hardware (a dedicated set of transistors) to solve it, it's a technical decision. We will see what it means in real world when we have numbers.

Usually not having dedicated, fixed function hardware for a task, mean that you have to use non specialized hw to do it, so you usually take more resources to do it. But it has its benefits. Dedicated fixed function hardware do take resources too (it's made of transistors that could be used to put in there some more general computing resources). And it rises the complexity and costs of developement.

We will see what this implementation choice they have made means in the end when we have data... probably it will take a higher performance impact when doing tesselation than Radeon cards, specially with shader intensive games, but maybe it's not that noticeably.

[Florinmocanu]

your right. But Cuda means another software layer between directx and execution, which i don't think it's beneficial.
Of course, everything goes to a more non specialized way to execute commands, but if that would be done through a single software intermediary, like Directx, for all GPUs, that would be ok. When you add another one, CUDA, than that doesn't make that much sense.