AMD's upcoming Radeon HD 8000 "Sea Islands" cards will reportedly be packing in more transistors making it physically larger than previous-gen "Tahiti" GPUs, and will be produced using a 28nm manufacturing process. The new GPUs will feature an updated Graphics Core Next architecture, with the 8970 bolstered by an increase of 5.1 billion transistors and 2,560 stream processors, and the 8950 speculated to have lesser stream processors at 2,304. Both cards will be running at GPU speeds of 1,050 MHz, while the memory will be clocked at 6,000 MHz and 5,500 MHz, respectively. The duo will also be sharing the same 384-bit memory bus with 3GB of GDDR5 memory. A beefier HD 8990 will have two underclocked 8970s combined with 6GB RAM. On the 8800 side, its GPUs are said to have a 3.4 billion transistor count, 256-bit bus width, and stream processors of 1,792 for the 8870 and 1,536 on the 8850. Lastly, the 8770 will have 192-bit memory bus and 2.1 billion transistors, an improvement over the HD 7700 which it replaces.
As the information originates from an unconfirmed source, for the meantime it is best to treat these details with a pinch of salt, although the specs do appear somewhat solid, if only on paper.