AMD's RV775XT is supposed to compete with the Geforce GTX 285
According to the rumor mill, AMD'S RV775XT GPU is a tuned RV770 chip with increased clock speeds.
AMD wants to put pressure on Nvidia with the RV775XT and RV740 GPUs.
Quelle: PC Games Hardware
As a competitor AMD seems to aim for the 55 nanometer Geforce GTX 285 which is expected to be released in January. Given the information that the new Nvidia chip won't have additional Shader ALUs but is supposed to be about 10 percent faster than the GTX 280, increased clock speeds might be enough for AMD's RV775XT to threaten the Geforce GTX 285. In order to achieve this, AMD is said to have selected the best RV770 GPUs for months already.
As VR-Zone wants to have learned, it seems like AMD is focusing on the RV740 at the moment. In contrast to the RV775XT the RV740 GPUs are supposed to be used on (upper) middle-class graphics cards - the name HD 4700 series has been brought up several times in the past already.