With the first three DX10 games out there in the wild, the chaps over at AnandTech take a close look at what we can expect from the current DX10 implementation. Here's an excerpt:

For now, AMD does seem to have an advantage in Call of Juarez, while NVIDIA leads the way in Company of Heroes and Lost Planet. But as far as NVIDIA vs. AMD in DirectX 10 performance, we really don't want to call a winner right now. It's just way too early, and there are many different factors behind what we are seeing here. As the dust settles and everyone gets fully optimized DirectX 10 drivers out the door with a wider variety of games, then we'll be happy to take a second look.

The more important fact to realize is that DirectX 10 is finally here. While developers are used to programmable hardware after years with DirectX 9, there is still room for experimentation and learning with geometry shaders, more flexibility, lower state change and object overhead, and (especially) faster hardware. But DirectX 10 isn't an instant pass to huge performance and incredible effects.

Let's look at it like this: there are really three ways a game can come to support DirectX 10, and almost all games over the next few years will ship with a DX9 path as well. The easiest thing is to do a straight port of features from DirectX 9 (which should generally be slightly faster than the DirectX 9 counterpart if drivers are of equal quality). We could also see games offer a DirectX 10 version with enhanced features that could still be implemented in DX9 in order to offer an incentive for users to move to a DX10 capable platform. The most aggressive option is to implement a game focused around effects that can only be effectively achieved through DirectX 10.

Games which could absolutely only be done in DX10 won't hit for quite a while for a number of reasons. The majority of users will still be on DX9 platforms. It is logical to spend the most effort developing for the user base that will actually be paying for the games. Developers are certainly interested in taking advantage of DX10, but all games for the next couple of years will definitely have a DX9 path. It doesn't make sense to rewrite everything from the ground up if you don't have to.