Xenos a Real and fully compliant DirectX 10 GPU?

[gustkiller]

Hi ppl! i´ve been reading about xenos gpu and i were sure that it isnt a directx 10 gpu but just read the info below from an Ati and it changed everithing...

As a milestone of graphical technology, DirectX 10 is expected to rule the future game together with Windows Vista. We have interviewed ATi’s Senior Product Manager of Desktop Discrete Graphics, Stan Ossias about the upcoming DirectX10 and Unified Shading architecture last week.

DirectX 9 and today’s hardware impose a number of unique constraints on game developers.
Every character, weapon, material, etc. in a game is an object, and each frame of a 3D game, there can be hundreds of objects. Object have to pass from the application, to the DirectX 9 API, through to the driver, which prepares the data in order for the hardware to process it and output a 3D image to a monitor. Every time an object is passed through the API, DirectX adds overhead which consists of instructions and setting for the driver. The more is the object, the more is the overhead that needs to be processed. The additional overhead can mean a hit on performance. As a result, developers have to be very creative in how they use objects in order to keep the game playing at a satisfactory rate. Stan indicates that games in today use execution time being divided between 40% for the API and driver, and 60% for the game itself. DirectX 10 is designed to reduce much of the overhead by introducing Dynamic indexing state and loading state snapshots automatically. Thus the game itself could now spare 80% of the procession, allowing developers to put more objects into their games to make it more realistic.

Featured Shader Model 4.0, DirectX 10 provides 32Bit color depth unified pixel rendering to satisfy any range of game design. Besides, DirectX 10 enables developers to handle physics calculation and audio part more easily. It also benefits to CAD/CAM and special effect designers!

In order to fully squeeze the power, Stan indicated that the next generation of graphic card would introduce unified shading architecture. For traditional GPU, Vertex Shader and Pixel Shader processing are dedicated by different engines. Figure below show an example of the utilization of two different engines in processing. It’s possible that Vertex Shader is only partially loaded while Pixel Shader is fully loaded, and vice versa. In DirectX 10, they are further separated into Vertex Shader, Geometry Shader, and Pixel Shader. The Unified Shader architecture is therefore recommended by Microsoft to execute vertex, geometry and pixel in the same engine, maximizing shader performance efficiencies.

The concept of Unified Shader architecture makes GPU’s role moving from game rendering to game computing. It’s suitable for Heterogeneous Computing like Physics calculation, video encoding, etc., making graphic card be more applicable in different field of applications.

Games are being developed today for ATI’s Unified Shading Architecture on XBox360. Stan said with confident that ATi could develop the first DirectX 10 based GPU with Unified Shader architecture for PC. He expected that as DirectX 10 supports for both Xbox360 and PC platform, providing standard interface like DirectPlay, Direct Input, and DirectMusic, developers could easily develop games for both platforms, making a win-win situation.

 

[gustkiller]

sorry i forgot the source: http://www.hkepc.com/bbs/itnews.php?tid=637174

 

[Bobbler]

It's still not. It's probably closer than any other DX9 GPU made, but it's not a DX10 compliant GPU (not that it's even relevant considering it's a closed box and doesn't necessarily use/follow DirectX the way the PC market does).

 

[Tahir2]

I suppose at the very least it does show how forward looking ATI has been with the design of the XBOX360 GPU. It would have been a safer and easier bet for ATI to re-use the R520/580 technology in some way as NVIDIA re-used the G71 technology when designing the RSX.

Please note I am not saying ATI or NVIDIA were right in their choices, there were other factors present e.g. the late arrival of NVIDIA on the PS3 scene and the knowledge acquired by developing the GameCube GPU and using eDRAM on the ATI part. And then you have the differing design goals, manufacturing technologies, time to market and design philosophies of the companies.

 

[Jawed]

There are some key things missing from Xenos that make it not D3D10, such as support for integers and the whole set of bit-wise operations upon integers; also data formats for render targets and textures are slightly mismatched as compared with D3D10.

The big missing concept in Xenos is geometry shading. Programmers have to approximate D3D10's functionality here - though as far as I can tell the vertex-shading functionality of Xenos is so general-purpose that things like geometry amplification are achievable. I'm still unclear, though, whether this actually requires a loop of data out to memory and back in again (i.e. via memexport).

There are also features in Xenos that may well come to PC GPUs, such as memexport (more general purpose than streamout in D3D10); multiple concurrent render states; programmer controlled scheduling (e.g. allowing the programmer to set-up a sequence of pre-fetches, rather than letting the GPU handle them piece-meal).

I say all this as someone who's never written a line of Direct X code, or shader language :smile:

Jawed

 

[swaaye]

Just think...they've had this futuristic technology on the market in 360 for almost a year now. That's some serious real-world usage to work the kinks out for R600.

 

[elementOfpower]

^ Yep, and it's the reason R600 will be a monster and most likely my next GPU.

 

[Megadrive1988]

it's already been answered, but......

nope Xenos is definitally *not* a fully compliant DirectX 10 GPU.


from what I understand Xenos cannot be completely "nailed down" as either a DirectX 9 or DirectX 10 GPU. it's a mix of both, with some features that even DirectX 10 does not have, however, Xenos is missing a number of DirectX 10 features (Geometry Shader, full SM4.0 capability).

to avoid confusion it's probably best to think of Xenos as a;
DirectX 9, "SM3 Plus", custom featured GPU.

 

[gustkiller]

thanks for the answers now i finally understood what xenos is