Half-Life 2 Performance Benchmark Preview
by Anand Lal Shimpi on September 12, 2003 12:34 AM EST- Posted in
- GPUs
More on Mixed-Mode for NV3x
We briefly mentioned the Mixed Mode of operation for NV3x GPUs that Valve implemented in Half-Life 2, but there is much more to it than just a special NV3x code path. In fact, the mixed mode NV3x code path was really only intended for the GeForce FX 5900 Ultra (NV35). The mainstream FX chips (5200/5600) require a slightly different code path.
Here you can see the 40% performance boost NVIDIA gets from the special NV3x
code path.
The GeForce FX 5600 (NV31) uses a code path that is internally referred to as dx82; this path is a combination of DX9 (pixel shader 2.0) and DX8.1 (pixel shader 1.4) code, and thus, doesn't look as good as what you'll see on the 5900 Ultra.
Although the 5900 Ultra performs reasonably well with the special NV3x mixed mode path, the 5600 and 5200 cards do not perform well at all. Valve's recommendation to owners of 5600/5200 cards is to run the DX8 (pixel shader 1.4) code path in order to receive playable performance under Half-Life 2. The performance improvement gained by dropping to the DX8 code path is seen most on the GeForce FX 5200; although, there is a slight improvement on the 5600 as you can see below:
The sacrifices that you encounter by running either the mixed mode path or the DX8 path are obviously visual. The 5900 Ultra, running in mixed mode, will exhibit some banding effects as a result of a loss in precision (FP16 vs. FP32), but still looks good - just not as good as the full DX9 code path. There is a noticeable difference between this mixed mode and the dx82 mode, as well as the straight DX8 path. For example, you'll notice that shader effects on the water aren't as impressive as they are in the native DX9 path.
Are the visual tradeoffs perceptive? Yes. The native DX9 path clearly looks better than anything else, especially the DX8.0/8.1 modes.
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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 : +1I 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.