By now you've heard that our Half-Life 2 benchmarking time took place at an ATI event called "Shader Day." The point of Shader Day was to educate the press about shaders, their importance and give a little insight into how ATI's R3x0 architecture is optimized for the type of shader performance necessary for DirectX 9 applications. Granted, there's a huge marketing push from ATI, despite efforts to tone down the usual marketing that is present at these sorts of events.

One of the presenters at Shader Day was Gabe Newell of Valve, and it was in Gabe's presentation that the information we published here yesterday. According to Gabe, during the development of Half-Life 2, the development team encountered some very unusual performance numbers. Taken directly from Gabe's slide in the presentation, here's the performance they saw initially:


Taken from Valve Presentation

As you can guess, the folks at Valve were quite shocked. With NVIDIA's fastest offering unable to outperform a Radeon 9600 Pro (the Pro suffix was omitted from Gabe's chart), something was wrong, given that in any other game, the GeForce FX 5900 Ultra would be much closer to the Radeon 9800 Pro in performance.

Working closely with NVIDIA (according to Gabe), Valve ended up developing a special codepath for NVIDIA's NV3x architecture that made some tradeoffs in order to improve performance on NVIDIA's FX cards. The tradeoffs, as explained by Gabe, were mainly in using 16-bit precision instead of 32-bit precision for certain floats and defaulting to Pixel Shader 1.4 (DX8.1) shaders instead of newer Pixel Shader 2.0 (DX9) shaders in certain cases. Valve refers to this new NV3x code path as a "mixed mode" of operation, as it is a mixture of full precision (32-bit) and partial precision (16-bit) floats as well as pixel shader 2.0 and 1.4 shader code. There's clearly a visual tradeoff made here, which we will get to shortly, but the tradeoff was necessary in order to improve performance.

The resulting performance that the Valve team saw was as follows:


Taken from Valve Presentation

We had to recap the issues here for those who haven't been keeping up with the situation as it unfolded over the past 24 hours, but now that you've seen what Valve has shown us, it's time to dig a bit deeper and answer some very important questions (and of course, get to our own benchmarks under Half-Life 2).

Index ATI & Valve - Defining the Relationship
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  • Anonymous User - Friday, September 12, 2003 - link

    another thing i just noticed looking at the doom 3 and hl2 benchies.

    take a look at the performance of 9800pro and 9600pro...

    in hl2, the 9800pro is about 27% ahead of the 9600pro, in doom 3 the 9800pro is near 50% faster than the 9600pro. the whole thing just feels weird.

    enigma
  • Anonymous User - Friday, September 12, 2003 - link

    I'm surprised that Anand mentioned nothing about the comparisons between 4x2 and 8x1 pipelines? Does he even know that MS is working to included paired textures with simutainious wait states for the nV arcitexture? You see the DX9 SDK was developed thinking only one path and since each texture has a defined FIFO during the pass the second pipe in the nV is dormant until the first pipe FIFO operation is complete, with paired textures in the pipe using syncronus wait states this 'problem' will be greatly relieved.
  • Anonymous User - Friday, September 12, 2003 - link

    its fake.... HL2 test are not ready today , great fake Anandtech :)
  • rogerw99 - Friday, September 12, 2003 - link

    #28
    Ooo Ooo Ooo... I know the answer to that one.
    It was Mrs. White, but it wasn't with the gun, it was the lead pipe.
  • Anonymous User - Friday, September 12, 2003 - link

    ATI The Way It Should Be Played
  • Anonymous User - Friday, September 12, 2003 - link

    Quote: 'So why is it that in the age of incredibly fast, absurdly powerful DirectX 9 hardware do we find it necessary to bicker about everything but the hardware? Because, for the most part, we've had absolutely nothing better to do with this hardware.'

    Don't we? Wrong!

    http://www.cs.virginia.edu/~gfx/pubs/multigridGPU/

    ;)
  • Anonymous User - Friday, September 12, 2003 - link

    one thing that i think is kinda interesting. check out this benchmark hardocp did - fx5900 ultra vs. radeon 9800 pro in doom 3 (with help from id software).

    http://www.hardocp.com/article.html?art=NDc0LDE=

    after reading this, read carmack's Jan 03 .plan, where he states that under the default openGL codepath, the fx architecture is about half as fast as the r300 - something that is pretty much resembled in the hl2 benchmarks. furthermore he states that using the default path the r300 is clearly superior (+100%), but when converting to vendor-specific codepaths, the fx series is the clear winner.

    conclusions? none, but some possibilities
    .) ati is better in directx, nvidia in opengl
    .) id can actually code, valve cannot
    .) and your usual conspiracy theories, feel free to use one you specifically like

    bottom line. neither ati nor nvidia cards are the "right ones" at the moment, wait for the next generation of video cards and upgrade THEN.

    enigma
  • Anonymous User - Friday, September 12, 2003 - link

    I'm so glad i converted to Ati, i have never regret it & now it feels even better. Ati rules
  • notoriousformula - Friday, September 12, 2003 - link

    i'm sure Nvidia will strike back.. prolly with DOOM III..well till then i'll enjoy my little army of ATI cards: ATI 9800NP>PRO, ATI 9700, ATI 9600PRO :P..long live ATI!!! :D
  • Anonymous User - Friday, September 12, 2003 - link

    Anand should have benchmarked on a more widely used computer like a 2400 or 2500+ AMD. Who here has the money to buy a p4 3Gb 8000mhz FSB cpu?

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