A controversy surrounding DirectX 10.1 performance in Assassin's Creed, in which ATI fans accused developers of removing features that made ATI cards run faster, has yet to be resolved.
The website Rage3D noted that DX 10.1 - supported on ATI, but not Nvidia cards - yielded up to 20 percent performance gains in the game with Vista Service Pack 1.
But in a subsequent patch, Ubisoft stripped out the code entirely and said nothing about fixing or reimplimenting it.
Speculation had it that Ubisoft bowed to pressure exercised by Nvidia, which maintains what it calls a "comarketing" relationship called "The Way It's Meant to be Played."
Another hardware website, Tech Report, said, "Our conversations with multiple credible sources in the industry gave some credence to this scenario, suggesting the marketing partnership with Nvidia may have been a disincentive for Ubisoft to complete its DirectX 10.1 development efforts."
Both Ubisoft and Nvidia have said no money ever exchanged hands in their business relationship although engineering resources and advertising promotions have been part of the deal.