Confusion with DX10 vid cards

[orchidsofwrath]

I'm a little confused by the new DX10 GPUs coming out. I always though that directx was something that had to do with your operating system, and that to get dx10, you simply had to download the new version. But since the new cards specify themselves as being a "dx10" card, I became a little confused. Will my so called "dx9" card (7600gt) be able to run in dx10 for the new games? And if not then will my only options for a new dx10 card be a 8800 series card? Thanks in advance.

 

[Valtiel]

DirectX 10 cards play DirectX 10 games at full DirectX 10 specifications, except when limited by your card's horsepower.

DirectX 9 cards can only render DirectX 9 effects/textures/whatever.

That's a pretty rough definition but thats basically it.

 

[The_Abyss]

And to add of course that DX10 cards will play DX9 and lower games.

 

[Valtiel]

Hehe, yeah almost forgot that part. Usually (if not always) a DX10 card will perform better than a DX9 card in a DX9 environment.

 

[miahallen]

...If you want to play DX10 games then you need one of the new video cards.

Not totally true, DX9 hardware should run DX10 games, but the games will only be showing up to DX9 level visual effects. You'll be missing out on any of the new DX10 effects unless you upgrade your hardware.

There is one area I think DX10 may allow an exception. That's with geometery shaders, I'm wondering if DX10 will allow the CPU to proccess the geometery shaders (abeit, at the cost of performance)?

 

[blade85]

And if not then will my only options for a new dx10 card be a 8800 series card? Thanks in advance.

For the current moment..yes that 8800 series is the only card that supports DX10. However give it a few months and ATI will release its version and Nvidia may come up with a more "price friendly" version of a dx10 card.

 

[Vokofpolisiekar]

Direct X is an API, that sets out standards for certain levels of Graphics generations, aswell as all multimedia support (keyboard,sound,mouse etc). This API allows game developers to design games under one "global" spec, so as to not have to design for each graphics card architecture.

In this spec, if we talk about graphics cards, we work with shaders as main identification of a certain DX level.

Shaders, pixel or vertex, are the means of how graphics are rendered on the screen. As the years fly past, newer shader instructions and code are used, which have to be supported by new graphics card in order to be compliant. This is hardware reliant, and hence you get DX8/9/10.

As an example:
DX8 had Pixel Shader version 1.0, and the later 8.1 had I think up to PS 1.3
DX9 had PS 2.0, and then DX9b had PS2.1b and DX9c had PS3.0
DX10 - this is a complete new API, and works completely different to the previous generation DX's due to unified architecture (dynamic load adjust to Pixel and/or Vertex shaders)

So, with each new DX, graphics cards need more "logic" to perform the added instruction. These "logics" refer to increased transistor count on the GPU. But, 5 years ago (very rough guess!) we had 150nm (the smallest wire connecting transistors on a GPU in nanometer) GPU chips, and this made it rather difficult to include a large number of transistors to the gpu, due to size, cost and heat constraints. This causes the growth in GPU power, and currently we are at a level where we can cram alot of transistors onto a GPU while costs, heat and size is managable. Currently, GPU's run on 110-80nm chips.

So, DX10 requires a new GPU, which right now can only be found on the 8800 or R500 in the Xbox (which isn't fully DX10, but hybrid between DX9 and DX10). Ati will release their DX10 card early in 2007, and I'd recon that the wait for it will be better, as price wars will then make the chips little cheaper.

As to the fact that you could install DX9, on DX8 chips previosuly, it boils down to backwards compatibality. Even if you run a DX8 card, you still use the latest DX9, as DX8 might be improved in new updates (for graphics). As already stated, DX does not only cover graphics, but input devices and sound aswell.

Now the sad part: DX9 can run in the Vista environment, but in a less supported (indirect) manner. So, certain VISTA features won't be able to run, aswell as the fact that DX9 games will be slowish in VISTA, aswell as running DX10 games in Vista using DX9 render path, resulting in the same scenario as before.

I'd recon, that VISTA will only be the sought after in Q2 of 2007 with regards to games in DX10. There is just too few, to warrant such an upgrade and the fact that your old DX9 games will be slow to begin with.
Don't get me wrong, I'm looking forward to DX10, but it will take time for this to establish itself...