Radeon HD 6770M is a fast-middle-class GPU based on the 40nm Terrascale 2 architecture.
It's based on the Turks Core (therefore related to Radeon HD 6670) and offers 480 Shader Processing Units, 24 TMUs and 8 ROPs on a 128-bit memory interface of fast GDDR5. Its central clock runs at 725MHz and the memory clock operates at 800MHz.
Its performance is superior to both Radeon HD 6830M & Radeon HD 6850M due to being paired with fast GDDR5.
Using a 720p resolution, most of today's games are only playable at medium or high settings but with very fluent frame rates (45+).