A forum member on Chinese website has leaked a 3D Mark Vantage Extreme benchmark, alongwith a GPU-Z screenshot, alleged to be from a next-gen ATI Radeon HD 6870. The important result is the 3D Mark Vantage score, which X11963. Considering the GTX 480 offers under X10000, and the HD 5870 is in the X9000 range, this is an impressive result for what is rumoured to be a minor intermediate generation on the same 40nm process.
Source: VR Zone