The Radeon HD 7870 is now one and a half years old. Its GPU, Pitcairn, is a downscale from the HD 7900 “Tahiti” silicon that introduced AMD’s Graphics Core Next architecture. Targeting a wide price-range, the HD 7800 series falls into the market-segment both AMD and NVIDIA have referred to as the “sweet spot”. Apart from 1280 stream processors, Pitcairn has 80 Texture Memory Units (TMUs), 32 ROPs (Raster Operations), and a 256-bit wide GDDR5 memory interface holding 2 GB of memory.
Full Review: http://www.techpowerup.com/reviews/Powercolor/HD_7870_Devil/