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Old 11-20-10, 03:28 AM   #6
DSC
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Join Date: Nov 2002
Posts: 888
Default Re: ATi benches inflated by reduced AF

Sazar, are you an idiot? Did you even READ the link? It's not Nvidia thats spilling the details, it's 4 major German review sites.

Quote:
Getting directly to the point, major German Tech Websites ComputerBase and PC Games Hardware (PCGH) both report that they must use the “High” Catalyst AI texture filtering setting for AMD 6000 series GPUs instead of the default “Quality” setting in order to provide image quality that comes close to NVIDIA’s default texture filtering setting. 3DCenter.org has a similar story, as does TweakPC. The behavior was verified in many game scenarios. AMD obtains up to a 10% performance advantage by lowering their default texture filtering quality according to ComputerBase.

AMD’s optimizations weren’t limited to the Radeon 6800 series. According to the review sites, AMD also lowered the default AF quality of the HD 5800 series when using the Catalyst 10.10 drivers, such that users must disable Catalyst AI altogether to get default image quality closer to NVIDIA’s “default” driver settings.

Going forward, ComputerBase and PCGH both said they would test AMD 6800 series boards with Cat AI set to ”High”, not the default “Quality” mode, and they would disable Cat AI entirely for 5800 series boards (based on their findings, other 5000 series boards do not appear to be affected by the driver change).
Even more disturbing is how AMD is gaming the AF testing tools.

Quote:
ComputerBase also says that AMD drivers appear to treat games differently than the popular “AF Tester” (anisotropic filtering) benchmark tool from 3DCenter.org. They indicate that lower quality anisotropic filtering is used in actual games, but higher quality anisotropic filtering is displayed when the AF Tester tool is detected and run. Essentially, the anisotropic filtering quality highlighted by the AF Tester tool on AMD GPUs is not indicative of the lower quality of anisotropic filtering seen in real games on AMD GPUs.

NVIDIA’s own driver team has verified specific behaviors in AMD’s drivers that tend to affect certain anisotropic testing tools. Specifically, AMD drivers appear to disable texture filtering optimizations when smaller window sizes are detected, like the AF Tester tool uses, and they enable their optimizations for larger window sizes. The definition of “larger” and “smaller” varies depending on the API and hardware used. For example with DX10 and 68xx boards, it seems they disable optimizations with window sizes smaller than 500 pixels on a side. For DX9 apps like the AF Tester, the limit is higher, on the order of 1000 pixels per side. Our driver team also noticed that the optimizations are more aggressive on RV840/940 than RV870, with optimizations performed across a larger range of LODs for the RV840/940.
If this is not the most blatant cheating ever, I don't know what it is.
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