Xbox gpu Nv2a

Discussion in 'Architecture and Products' started by Shapeshifter, Nov 13, 2004.

  1. Shapeshifter

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    Are there any documents that list what the xbox is cable of in terms of Direct X features? (I know its 8.1 using shader 1.1 with some 1.3, but some stupid fan boys are arguing how the xbox is cable of dx 9 via "programing" :lol: and will be able to do half life 2 well :roll: )

    Sufice to say they are driving me up the wall while I try to explain to them how its not possible and I want to shove some common sense down their collective throats.... not that they will believe me.
     
  2. Jallen

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    Its definitely only capable of DirectX 8.1 level pixel shaders. Half-life 2 is still possible on the XBox because it doesn't require DirectX 9 level shaders, it has a DX8 rendering backend.
     
  3. Kaotik

    Kaotik Drunk Member
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    XGPU aka NV2A is capable of VS1.1 and PS1.1 or 1.3, not sure which, so in those terms it matches either GF3 or GF4Ti, and matches either DX8.0 or partial DX8.1 (yes, some will argue this, I'm sure, but I'm still saying less than PS1.4 = partial DX8.1 :p )

    HL2 can run even on DX7, possibly even DX6 hardware, so that's not a problem for XBox,but it won't look visually the same as with PC's DX9 shaders.
     
  4. Inane_Dork

    Inane_Dork Rebmem Roines
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    Technical issues aside, I think this is the crux of the issue. They're dumb, and in their stupidity they think themselves smart. They will not believe you because you disagree with them. Lacking the ability to force a crisis in their beliefs, you will never convince them.

    All the technical help in the world ain't gonna help, because this is a people problem.
     
  5. nAo

    nAo Nutella Nutellae
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    NV2A is capable of more of VS1.1 and PS1.3 (but it's NOT PS1.4 o PS2.0 compliant), actually on the VS side it can do things you can't do even on a SM3.0 part.
     
  6. Murakami

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    Link, please.
     
  7. nAo

    nAo Nutella Nutellae
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    I can't link XBOX sdk ;)
     
  8. ERP

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    To be fair I believe all NV2X hardware can do the same thing, it's just not exposed in any API.
     
  9. Fox5

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    But isn't 8.1 ps1.4? Can the xbox achieve ps1.4 effects through some other method?

    Halo on PC mostly looked like ps1.4, with a few effects only done right in ps2.0, and 1.3 supporting cards left out quite a few features.
     
  10. Dave Baumann

    Dave Baumann Gamerscore Wh...
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    PS1.2, 1.3 and 1.4 were all introduced under "DX8.1". 1.2 and 1.3 were fairly minor differentiations from PS1.1, however PS1.4 was somewhat different, with different instructions that could replace some and also more instructions, etc.
     
  11. Fox5

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    Is ps1.3 just a faster version of ps1.1(more instructions in 1 pass?) or does it allow anything new to be done?
     
  12. Nick Spolec

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    And what exactly would these things be?
     
  13. Dave Baumann

    Dave Baumann Gamerscore Wh...
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    Only a few minor instruction differences. The MSDN site used to have a table detailing the differences between the DX8 shader models. however I can't seem to find it now.
     
  14. Ostsol

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    Pixel Shader Differences

    EDIT:

    PS1.2 added cmp, dp4, texdp3, texdp3tex, texm3x3, and texreg2rgb
    PS1.3 added texm3x2depth

    Pretty much everything else is the same between 1.1 to 1.3.
     
  15. Fox5

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    Unless the per phase means something really significant it doesn't seem like ps1.4 added very much, at least not compared to ps2.0.
     
  16. Dio

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    1.4 is a huge advance over previous versions. The earlier versions gave you virtually no dependent texturing at all.
     
  17. Fox5

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    I noticed the differences in the instructions, but I didn't know quite what they meant. I just thought the ps1.4 instructions were a faster way of doing the same thing.(maybe less memory dependent and more graphics chip dependent?)
     
  18. Luminescent

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    As Dave has mentioned in the past, NV2A has an FP precision texture address unit, NV30 style rops (2 stencils per clock, per rop), and 2 FX (integer combiner) units per pixel pipeline. Aside from this it can do things like collision detection with its vertex units.
     
  19. Dave Baumann

    Dave Baumann Gamerscore Wh...
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    IIRC all NV2x had FP precision texture units.
     
  20. Megadrive1988

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    oh my. like what?

    dare we suggest that NV2A can do things that you can't do on R500 / Xbox2?

    that would be beyond funny. :shock:
     
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