AMD Radeon HD 6970M
960 Shaders, 48 TMUs, 32 ROPs, Core Clocks: 580MHz (6950M) or 680MHz (6970M)
256-bit Memory Bus, GDDR5, Effective Memory Clocks: 3.6GHz
Desktop Counterpart: Radeon HD 6850 (Barts)
GTX470 ~ GTX560Ti, give or take 5%.
So a desktop
GTX470 will be about 30-35% faster than the 6970M.
However, that's still mighty impressive for a mobile part! The problem is for 2560 by 1440 pixels, it's not enough power for modern games. But it should play games like Portal 2, WOW, Starcraft 2 just fine. Just don't expect to run Crysis 2, Metro 2033, BF3, SKYRIM on a 6970M at 2560x1440. But in all fairness, a single GTX470 can't do that either.