TweakTown posted a comparison between AMD's ATI Radeon HD 5870 vs. HD 4890 GPU
When we had a look at the Sapphire Radeon HD 5870 we saw how it compared to a number of cards including the older HD 4890 and its main competition, the GTX 285 from NVIDIA. With a reference HD 5870 on our hands we thought that we could take a look at it in a slightly different way.AMD's ATI Radeon HD 5870 vs. HD 4890 GPU Comparison
What we'll do here today is see how the card compares to the HD 4890 and that card only. What we want to find out is the kind of performance improvements the new generation card offers over the previous generation without being distracted by any other models. While the HD 5870 might be replacing the HD 4890 when it comes to the red team’s fastest single GPU card, the older HD 4890 continues to be available with many companies having added their own flair to the model recently.