According to NVIDIA, AMD is playing a little trick on you. In an extensive blog post on the company's website, Technical Marketing Director Nick Stam explained that Catalyst drivers were sneakily sacrificing image quality to gain a performance advantage over GeForce GPUs.
The post highlights the findings of a number of German websites that found a discrepancy in the texture filtering settings of the recently released Catalyst 10.10 drivers with HD 5800 and HD 6800-series GPUs. Apparently, this update reduced the default settings for Catalyst AI Mipmap detail level from 'High' to 'Quality', resulting in a significant degradation in visual fidelity. In fact, only manually returning the setting to high would match the quality produced by NVIDIA's drivers at default settings.
The result in terms of performance is that AMD cards will gain an approximate ten per cent advantage by using the lower quality texture-filtering. Stam points out that this doesn't allow for a fair comparison between GeForce and Radeon GPUs and implies that the Catalyst driver developers are purposely cooking the books. Obviously, NVIDIA wouldn't resort to such tactics, having been caught using such underhand methods in the past.
If this all sounds a little bit familiar, it's because it's very similar to an argument that came up a few months ago when NVIDIA asked reviewers to disable FP16 demotion in AMD drivers when testing the GTS 450. Again, the GeForce-maker claimed that performance was unfairly being gained at the expense of image quality.
The sites in question have posted some videos of their findings, and there do seem to be some differences in the way the different quality settings render textures in synthetic tests. At the same time, whether these will make an appreciable difference to actual gamers in real-world usage scenarios is questionable. Hopefully AMD will respond to the accusations soon.
