AMD is cheating says Nvidia

Nvidia has its panties in a twist over AMD’s alleged 'cheating' in benchmarks... again.

Well, to be honest it’s been a long time since we’ve been entertained by this type of accusation.

In the good ol’ days it was easier, as it related to CPU detection and performance optimisation. Now it’s that subtly grey area of 'image quality'.

So here’s the current sorry story.

The good folks at Atomic PC, while reviewing a GTS 450 card, were intrigued by a passage in that extraordinary piece of literature called the 'reviewer’s guide' that came from Nvidia, a passage claiming that AMD used unfair optimisations in their Catalyst drivers that would reduce image quality to produce higher frame rates, that way cheating on benchmark scores.

They found this so amusing, in fact, that they decided to put it to the test.

The problem stems from AMD using what is called FP16 Demotion, a procedure controlled by Catalyst AI to reduce memory consumption in rendering high-dynamic range lighted scenes.

This is done by reducing RGB colour depth and dropping the alpha channel data. FP16 normally takes up 64 bits per pixel, FP16 Demotion brings this down to 32 bits. That’s 50 per cent savings right there.

So, Nvidia thought it would be OK to highlight that fact and include an executable file in their press pack to allow users to enable and disable FP16 Demotion, then advised reviewers to put it to use and even compare notes with AMD about it.

However, after looking into the matter and consulting both parties, Atomic PC found that both companies have sanctioned the procedure, and make use of this option whenever they need it. Nvidia itself published technical documents validating this option. Although marketing suggest otherwise, the engineers who write the DirectX technical guides gave it a thumbs up.

Potatoes, potartoes.

This is the point… Catalyst AI does use FP16 Demotion. It’s a trade-off, marginal at best, if you consider the benchmarking results at Atomic, and If you’re not happy with that you can always switch it off Catalyst AI.

Of course you know that the difference between 150 frames and 140 frames is nothing to the human eye. It’s the sub 30fps area that you should be wary of. To be fair, you can accept both explanations. Nvidia's policy is a "no-compromise" attitude, while AMD's position is "be efficient".

We’ll let you be the judge. It’s just funny to see that some things never change.