Looks like the full specifications of what seem to be the Barts Southern Island GPUs have been revealed in these leaked slides from AMD, showing off nearly twice the power of the previous generation, and something for Nvidia to stand up and take notice. The performance per watt have been upped a lot, and in terms of raw power, the HD 6750 and 6770 even outstrip the HD 5850 and 5870 current high-end cards. The HD 6770 gets a seriously fast core clock, with 900MHz at stock speeds, while the HD 6750 seems to have identical clock speeds of the HD 5850. The HD 6770 and 6750 are expected in time for Black Friday, late this November.
The chart also reveals more about the architecture of the new lineup, with the Barts' SIMD structure showing VLIW-4 shader clusters, compared to Cypress' VLIW-5 clusters. The clusters are evidently more efficient though, providing better performance in the same die area. The total shaders per SIMD of the HD 5870 (Cypress XT) and HD 6770 (Barts XT) remain equal, just arranged differently. One just has to wonder if the Barts GPU is so powerful, what will the Cayman XT (HD 6870) bring to the table, how mind-blowing the Antilles (HD 6970) will be. The below slightly older leak seems to confirm the same story.