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GeForce FX Architecture Explained

Posted by CowboyNeal on from the kicking-the-tires dept.

Brian writes "3DCenter has published one of the most in-depth articles on the internals of a 3D graphics chip (the NV30/GeForce FX in this case) that I've ever seen. The author has based his results on a patent NVIDIA filed last year and he has turned up some very interesting relevations regarding the GeForce FX that go a long way to explain why its performance is so different from the recent Radeons. Apparently, optimal shader code for the NV30 is substantially different from what is generated by the standard DX9 HLSL compiler. A new compiler may help to some extent, but other performance issues will likely need to be resolved by NVIDIA in the driver itself."

16 of 185 comments (clear)

  1. Say what by Anonymous Coward · · Score: 5, Funny
    performance is so different from

    Is that the politically correct way of saying "performance sucks"?

    1. Re:Say what by cbreaker · · Score: 5, Insightful

      haha yea I guess so. It'll be awhile before it's considered "okay" for any sort of media to say that an nVidia board has sucky performance.

      It keeps getting excused away by "archetecture changes" or "early driver issues" or "the full moon."

      Go go ATI! You brought competition back to the consumer 3D board scene, thank you!

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    2. Re:Say what by robbyjo · · Score: 4, Insightful

      Know that there are many ways to do one thing and there are pros and contras in each of them. In this case, it seems that NVidia's is not chosen and the way DX9 handles things undermines NVidia's method. It's not necessarily because NVidia sucks. Remember that there are politic struggles among Microsoft, NVidia, and ATI during the inception of DX9? I think NVidia now falls victim of it.

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    3. Re:Say what by Anonymous Coward · · Score: 5, Insightful

      The fun thing about HL-2 is it'll likely be the first game where you WON'T have to install a patch or updated Catalyst driver to actually play it with your ATI. WOOT. Go driver development...

    4. Re:Say what by jjeffries · · Score: 5, Funny
      > Know that there are many ways to do one thing and there are pros and contras in each of them.

      Lucky for me, I have 100 lives!
      Up-up-down-down-left-right-left-right-B-A-select(I have a brother)-start

    5. Re:Say what by afidel · · Score: 3, Informative

      Basically it comes down to MS partnered with Nvidia for DX8 and XBox-1, Nvidia asked MS to use some KY so MS chose ATI for DX9 and XBox-2.

      p.s.
      If you don't get this, MS was losing money on the XBox for a long time, some analysts say they still are, to minimize those losses they asked Nvidia to take a hit on the contract terms for the XBox hardware agreement, Nvidia being a relitivly small company said no thanks and that effectivly ended their relationship for now.

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    6. Re:Say what by Anonymous Coward · · Score: 4, Interesting

      No need for the tinfoil hat.

      The most complex part of a DX8 or DX9 chip is the Pixel Shader, so I'll concentrate on it. Nvidia spearheaded the development of PS1.1 for DX8.

      Then ATI stole the show with PS1.4 (DX8.1), which is much closer to PS2.0 than PS1.1. At this point, ATI got Microsoft's ear -- ATI was ahead of Nvidia in implementing programmable shaders in graphics hardware.

      So Microsoft had good reason to pay attention to ATI's ideas of DX9 (including how the HLSL should look like and what kind of assembly it should output), long before any Xbox 1 money issues with Nvidia, long before choosing the designer for Xbox 2 graphics/chipset.

      I guess ;-)

  2. maybe, just maybe... by PoPRawkZ · · Score: 5, Funny

    someone programmed the shaders to work with glide... i can't help hoping 3Dfx will perform some voodoo and ressurrect from nVidia's ashes. excuse me now, i must go stroke my voodoo5

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  3. Here's the real story: by Anonymous Coward · · Score: 5, Funny

    Experience:

    GeForce FX is really noisy

    Explanation:

    It sucks in large amounts of air to keep it cool. This is one of two ways a GeForce FX sucks. The other way is beyond the scope of this post.

  4. I wonder what a structured classroom approach... by tloh · · Score: 5, Interesting

    Weird timing. I'm currently writing code for a class on microcontrollers. Most electrical engineering students would at some time come across an advanced digital course on microprocessors where one learns about different machine architectures and how to write assembly code for them. Are there any /.ers who have systematically studies GPU chips as part of a class, like say on graphic algorithms or DSP?

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  5. Lies! by zapp · · Score: 4, Funny

    Does the FX architecture involve cheating on benchmarks? :)

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  6. Re:3 Nvidia Articles?!! by Anonymous Coward · · Score: 5, Funny

    Yes, it's common practice to pay websites to post articles about why your product sucks. Don't let anyone tell you that the bad press might possibly hurt business, that's a lie.

  7. On the other hand... by La+Temperanza · · Score: 3, Interesting

    NVidia has much better Linux drivers then ATI. Support 'em.

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  8. One assumption is probably wrong by hbog · · Score: 5, Interesting

    From the article - "Because of the length of the pipeline and the latencies of sampling textures it is possible that the pipeline is full before the first quad reaches its end. In this case the Gatekeeper has to wait as long as is takes the quad to reach the end. Every clock cycle that passes means wasted performance then. An increased number of quads in the pipeline lowers the risk of such pipeline stalls."

    I understand that the article writers are trying to come up with reasons that the Nvidia part is wasting performance, but this doesn't make sense. No architect in this right mind would ever design a pipeline that becomes full before the first instruction can exit. The means that you are fetching much faster than you are retiring instructions. That means you will always have a pipeline stall at the frontend and you will always be wasting cycles. I think the designers would have checked something like that. You can't afford pipeline stalls to happen regularly.

  9. Linux Drivers by maizena · · Score: 4, Informative

    In the Windows(argh) world I really couldn't care less about what card to use.
    ATI or NVIDIA, it's just a matter of taste and/or faith.

    But in the Linux world NVIDIA still rules.
    And it's not that NVIDIA's cards are better, but they at least have a descent Linux driver.

    The bottom line is: "If you use Linux, the best choice still is a NVIDIA card!"

  10. GeforceFX by BigFootApe · · Score: 5, Interesting

    This article seems to reiterate what everyone has been saying (Carmack, Valve, everyone). The GeforceFX architecture can only be made competitive for 3d engines using modern shaders with herculean effort. This is to be competitive, not dominantly superior.

    Honestly, I thought nVidia learned their lesson with the NV1 - don't make weird hardware.

    Now, what has to be making GeforceFX owners worried is Gabe Newell's warning that the new Detonator drivers might be making illegitimate 'optimizations' and, furthermore, covering them up by rendering high quality screen captures.