|Review Websites Discover AMD Driver Reduces Image Quality|
|Written by NVIDIA - Nick Stam|
|Saturday, 20 November 2010|
Review Websites Discover AMD Driver Reduces Image Quality
According to NVIDIA: PC gaming enthusiasts understand image quality (IQ) is a critical part of the PC gaming experience. They frequently upgrade their GPUs to play the latest games at high frame rates, while also dialing up the display resolution and graphical IQ effects to make their games both look and play great. Image quality is important, and if it were not important, we'd all be playing at 10x7 with no AA!
Important Benchmarking Issues and Questionable Optimizations
What Editors Discovered
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).
Filter Tester Observations
AF Tester Observations
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.
FP16 Render Observations
A Long and Winding Road
Both NVIDIA and AMD provide various control panel knobs to tune and tweak image quality parameters, but there are some important differences -- NVIDIA strives to deliver excellent IQ at default control panel settings, while also ensuring the user experiences the image quality intended by the game developer. NVIDIA will not hide optimizations that trade off image quality to obtain faster frame rates. Similarly, with each new driver release, NVIDIA will not reduce the quality of default IQ settings, unlike what appears to be happening with our competitor, per the stories recently published.
We are glad that multiple top tech sites have published their comparative IQ findings. If NVIDIA published such information on our own, without third-party validation, much of the review and technical community might just ignore it. A key goal in this blog is not to point out cheats or "false optimizations" in our competitor's drivers. Rather it is to get everyone to take a closer look at AMD's image quality in games, and fairly test our products versus AMD products. We also want people to beware of using certain anisotropic testing tools with AMD boards, as you will not get image quality results that correspond with game behavior.
AMD promotes "no compromise" enthusiast graphics, but it seems multiple reviewers beg to differ.
We have had internal discussions as to whether we should forego our position to not reduce image quality behind your back as AMD is doing. We believe our customers would rather we focus our resources to maximize performance and provide an awesome, immersive gaming experience without compromising image quality, than engage in a race to the IQ gutter with AMD.
EDITOR'S NOTE: This is a disturbing article, and the sources here are critical for legitimacy. NVIDIA is a direct competitor to AMD and is the author of this article, which may lead some readers to ignore the message. However, it was several independent review website's that first brought this issue to the forefront, and proved it exists. I personally trust these websites, particularly 3DCenter.org, and have found them to be unbiased over the years.
Benchmark Reviews can confirm that issues with filtering still exist, and pointed this out in our Radeon HD 6850 and Radeon HD 6870 launch articles. We also made it public that certain AMD partners were sending 'juiced' video card samples to reviews sites, ours included, with details published in our 1120-Core "Fixed" Radeon HD 6850 Review Samples Shipped to Media article. So could this be AMDs last ditch effort to compete with NVIDIA by manipulating performance?