The Radeon HD 4800-series has been a real success for AMD, and combined with Phenom II Processors they create a synergistic effect called the Dragon platform. The new Radeon RV790 GPU is the next well-bred concept from the ATI labs, and in this article Benchmark Reviews tests the performance of the new Sapphire Radeon HD 4890 GDDR5 video card against the rest of the high-end segment. Since the Radeon 4890 is the most-powerful single GPU video card produced by AMD, it's going to be a tough fight to beat out NVIDIA.