Bright Side of News published new rumors about AMD's Radeon HD 7000 series. The site claims the new lineup will be a mix of the existing VLIW4 and VLIW5 architectures with the next-gen "Graphics Core Next" (GCN).
The Brazos 2.0 graphics will reportedly be rebranded as Radeon HD 7200 and 7300 series, which are based on the Evergreen GPU (VLIW5), while the higher-end Trinity APUs will feature the Devastator GPU core Radeon HD 7450 and 7550, which is based on the Northern Islands VLIW4 architecture.
The Radeon HD 7500, 7600, 7700 (Cape Verde) and 7800 (Pitcairn) discrete graphics cards will all be based on the VLIW4 architecture, while the Radeon HD 7900 series will adopt the new Graphics Core Next architecture.
If you compare the VLIW4-based HD 6900 and the upcoming HD 7800 series, there isn't much difference between the two. According to our sources, HD 7800 "Pitcairn" is a 28nm die shrink of the popular HD 6900 "Cayman" GPU with minor performance adjustments. This will bring quite a compute power into the price sensitive $199-$249 bracket and we expect a lot of headaches for NVIDIA in that respect.
AMD kept the unified clock concept and given that Radeon HD 7970 is based on fully configured "Tahiti XT" GPU, 2048 cores (32 Compute Units) operate at 1GHz clock. 3GB of GDDR5 memory operates in Quad Data Rate mode i.e. 1.37GHz ODR ("effective 5.5GHz"). This results with record video memory bandwidth for a single GPU - 264GB/s.
The HD7950 is based on "Tahiti Pro" and packs 30 Compute Units for 1920 cores operating at 900MHz. The number of ROPs decreased to 60, while Texture units naturally reduced to 120 (as every CU connects to 2 ROPs and 4 TMUs). Our sources did not disclose if the memory controller is still 384-bit or a 256-bit one, but the memory clock was decreased to 1.25GHz, i.e. the same clock as previous gen models. Should 384-bit controller stay, the clock should be good for 240GB/s of bandwidth.
As far as dual-GPU "New Zealand", 6GB GDDR5 is expected to be clocked on the same level as the HD6990/7970, meaning you will be getting full performance out of the dual-GPU part.