An article on Forbes quotes AMD's Robert Hallock on NVIDIA's GameWorks program, saying this "represents a clear and present threat to gamers by deliberately crippling performance on AMD products to widen the margin in favor of NVIDIA products." He goes on to explain the program "precludes the developer from accepting AMD suggestions that would improve performance directly in the game code," while of course allow easier optimization for NVIDIA graphics cards, and says AMD is not allowed to use source code from these games to develop drivers. VG247 notes a response from NVIDIA has already appeared, as a series of tweets from John McDonald strongly refutes these contentions (though these are personal reactions, rather than any sort of official statement on the topic). Here they are strung together: "It is extremely frustrating to see an article criticizing work you did at a former employer and not being able to comment that the person who you are quoting from was just completely full of unsubstantiated bullshit. And while I never did, and certainly do not now, speak for nvidia, let me say that in the six years I was in devtech I *never*, not a single time, asked a developer to deny title access to AMD or to remove things that were beneficial to AMD."