Blythe: Well there's been this interest in being able to handle higher-order surfaces and subdivision surfaces for a long time, and we looked at that pretty early in DX10. We decided we just weren't there. We didn't have enough manpower resources to really solve the problem and do a good job of the other things we were trying to do. It wasn't clear that the hardware could really be there yet, either. There were other things along those lines, where we thought it was a good idea and after we did more investigation, we'd back off on it. Like having the front-end of the vertex gathering unit be more programmable, so you could walk multiple vertex arrays at the same time and do that in a programmable way. It turns out it just wasn't worth the trouble—the costs versus the benefit we would have seen.

ExtremeTech: With every new DirectX, it takes some time before the games really start to make use of it, and then even more time before they become a required least-common-denominator. Do you see that transition happening any faster with DirectX 10?

Donahue: Part of this is a business consideration as well. At the launch of Vista and DX10 hardware, there's fundamentally zero installed base, and it grows exponentially over time. If you look at history and how rapidly they evolved from having DX8 hardware move over to DX9 hardware, it was pretty quick. My guess is DX10 will be the same way and I think that you will see…I can't predict a good time-frame, but there will be titles in the not-too-distant future that are DirectX 10 only.

ExtremeTech: It didn't take long for games to take advantage of DirectX 9, but it took a really long time before any games required it. Do you think that's going to happen more quickly with DirectX 10?

Donahue: It's difficult to say if only because the consoles, as you mentioned before, Xbox 360 and PS3, are fundamentally DX9 parts. We're kind of back into a situation we were in before, where there's a lowest common denominator across hardware. If someone is going to do a game that is multiplatform and they want it to run on the consoles, they're going to have to do a DX9-style pipeline anyway. So from that perspective, there are companies that do just one generic cross-platform component and try to hit everything, then there's the guys that do the really exploitive type stuff.

I think you'll see DX10-only in the next two years, certainly. That's about as close as I can pin it, because part of it is going to depend on adoption and installed base of DirectX 10 hardware.

ExtremeTech: Have either of you seen DirectX 10 stuff up and running yet on real hardware yet? Or are you still stuck in the reference rasterizer, exploratory mode?

Donahue: Nice try, Jason! (laughs) Those are questions for the hardware companies, you know how that is.

This article was originally published on extremetech.com.