Improving Performance on NVIDIA

If the hypotheses mentioned on the previous page hold true, then there may be some ways around these performance issues. The most obvious is through updated drivers. NVIDIA does have a new driver release on the horizon, the Detonator 50 series of drivers. However, Valve instructed us not to use these drivers as they do not render fog in Half-Life 2. In fact, Valve was quite insistent that we only used publicly available drivers on publicly available hardware, which is a reason you won't see Half-Life 2 benchmarks in our upcoming Athlon 64 review.

Future drivers may be the key for higher performance to be enabled on NVIDIA platforms, but Gabe issued the following warning:

"I guess I am encouraging skepticism about future driver performance."

Only time will tell if updated drivers can close the performance gap, but as you are about to see, it is a decent sized gap.

One thing that is also worth noting is that the shader-specific workarounds for NVIDIA implemented by Valve will not immediately translate to all other games that are based off of Half-Life 2's Source engine. Remember that these restructured shaders are specific to the shaders used in Half-Life 2, which won't necessarily be the shaders used in a different game based off of the same engine.

Gabe also cautioned that reverting to 16-bit floating point values will only become more of an issue going forward as "newer DX9 functionality will be able to use fewer and fewer partial precision functions." Although the theory is that by the time this happens, NV4x will be upon us and will have hopefully fixed the problems that we're seeing today.

NVIDIA's Official Response

Of course, NVIDIA has their official PR response to these issues, which we've published below:

During the entire development of Half Life 2, NVIDIA has had close technical contact with Valve regarding the game. However, Valve has not made us aware of the issues Gabe discussed.

We're confused as to why Valve chose to use Release. 45 (Rel. 45) - because up to two weeks prior to the Shader Day we had been working closely with Valve to ensure that Release 50 (Rel. 50) provides the best experience possible on NVIDIA hardware.

Regarding the Half Life2 performance numbers that were published on the web, we believe these performance numbers are invalid because they do not use our Rel. 50 drivers. Engineering efforts on our Rel. 45 drivers stopped months ago in anticipation of Rel. 50. NVIDIA's optimizations for Half-Life 2 and other new games are included in our Rel.50 drivers - which reviewers currently have a beta version of today. Rel. 50 is the best driver we've ever built - it includes significant optimizations for the highly-programmable GeForce FX architecture and includes feature and performance benefits for over 100 million NVIDIA GPU customers.

Pending detailed information from Valve, we are unaware of any issues with Rel. 50 and the drop of Half-Life 2 that we have. The drop of Half-Life 2 that we currently have is more than 2 weeks old. It is not a cheat or an over optimization. Our current drop of Half-Life 2 is more than 2 weeks old. NVIDIA's Rel. 50 driver will be public before the game is available. Since we know that obtaining the best pixel shader performance from the GeForce FX GPUs currently requires some specialized work, our developer technology team works very closely with game developers. Part of this is understanding that in many cases promoting PS 1.4 (DirectX 8) to PS 2.0 (DirectX 9) provides no image quality benefit. Sometimes this involves converting 32-bit floating point precision shader operations into 16-bit floating point precision shaders in order to obtain the performance benefit of this mode with no image quality degradation. Our goal is to provide our consumers the best experience possible, and that means games must both look and run great.

The optimal code path for ATI and NVIDIA GPUs is different - so trying to test them with the same code path will always disadvantage one or the other. The default settings for each game have been chosen by both the developers and NVIDIA in order to produce the best results for our consumers.

In addition to the developer efforts, our driver team has developed a next-generation automatic shader optimizer that vastly improves GeForce FX pixel shader performance across the board. The fruits of these efforts will be seen in our Rel.50 driver release. Many other improvements have also been included in Rel.50, and these were all created either in response to, or in anticipation of the first wave of shipping DirectX 9 titles, such as Half-Life 2.

We are committed to working with Gabe to fully understand.

What's Wrong with NVIDIA? More on Mixed-Mode for NV3x
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  • Anonymous User - Friday, September 12, 2003 - link

    Anand, when using the Print Article feature in Mozilla 1.4, I was shown only graphs from one map throughout. For instance, after clicking Print Article, all graphs were of the bug level. Hitting F5 showed them all to be of techdemo. In both cases, some graphs didn't correspond to your comments.

    This may be b/c the article was just posted, but thought I'd give you a heads-up anyway.

    Thanks for the interesting read, and hopefully we'll see screenshots of the differences between the DX8.0. 8.1, 8.2, NV3x, and DX9 modes soon (the only thing lacking from this article, IMO)!
  • Anonymous User - Friday, September 12, 2003 - link

    .. goddammit, all the flashes are arranged improperly. (Techdemo on bugbait pages, city on techdemo...) FIX IT.
  • Anonymous User - Friday, September 12, 2003 - link

    I was hoping anand would compair a 128mb 9800pro to a 256mb one, guess I'll still have to wait =(
  • Anonymous User - Friday, September 12, 2003 - link

    Hey Anand, you have a 9500 Pro lying around?

    Eh, well, it doesn't need to be included anyway. We all know how it would do: 5% worse than the 9700 Pro.
  • Anonymous User - Friday, September 12, 2003 - link

    #5 & #6 : +1
    I ll keep my G4 Ti 4200@300/600.
    I m sure HL² will still rocks in DX 8.1
  • Anonymous User - Friday, September 12, 2003 - link

    Where are the numbers with AA/AF enabled? I know the article intimates that there's a negligible performance hit, but I'd still like to see the numbers.
  • Anonymous User - Friday, September 12, 2003 - link

    Man, the Ti series has been doing this for a while!

    http://www.amdmb.com/article-display.php?ArticleID...
  • Anonymous User - Friday, September 12, 2003 - link

    I feel the same way about the GF4Ti series. Never did like the FXes much...
  • Anonymous User - Friday, September 12, 2003 - link

    Hahahahaha.

    Go you Ti4600, GO! I BELIEVE IN THE Ti4600!

    If all I am going to lose is a bit of image quality, then no great loss. At least it isn't back to 640x480!

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

    Wow 9800 pro barely edges out 9700 pro. 9600 pro seems to be the best deal if people are still waiting to upgrade.

    Obviously Nvidia lost this round with nv30 and nv35.

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