If you ask us, both AMD and NVIDIA have reason to believe that their newly launched dual-GPU-on-single PCB graphics card, the AMD Radeon HD 6990 and the NVIDIA GeForce GTX 590, deserves to be the world's fastest graphics card. Based on our own testing, both cards are quite equally matched; AMD won some benchmarks, NVIDIA won some. Therefore, it all depends on which games you play, though NVIDIA definitely can claim to have the quieter card.
AMD Blog - So now I issue a challenge to our competitor: prove it, don’t just say it. Show us the substantiation. Because as it stands today, leading reviewers agree with us here, here, here, and here that the AMD Radeon HD 6990 sits on the top as the world’s fastest graphics card.
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