ATI Radeon HD 4850 deserves the prestigious title of the best graphics accelerator in the sub-$200 category. It provides very high performance at a comparatively low price and exceeds Nvidia GeForce 9800 GTX in a number of other aspects.
ATI Radeon HD 4870 is equipped with super-fast GDDR5 memory delivering impressive data transfer rate of 115.2GB/s even with 256bit bus. This solution performs extremely fast, which puts it next to more expensive GeForce GTX 260 and 280.
Xbit Labs have to say that unlike the competition, ATI Radeon HD 4800 supports DirectX 10.1 and features a more advanced UVD2 video processor. It also supports 7.1 HD sound over HDMI.