My problem is mentioned in THIS thread.
If you go through all the posts, you'll find that there are some users which are getting pretty good performance in all the games, even at FullHD resolutions. But, there are many users, who are facing some problem with the 6770M. I am one of those unfortunate sufferers.
Like I have mentioned numerous times before, I'm not getting good fps in any of the games. And yes, I do know how to set it to 'High Performance' etc, so please don't suggest me to do so time and again. I have updates the drivers, removed all the crapware, keep the laptop plugged in while gaming and even upgraded the RAM to 8 GB because the damn thing was showing me low on memory error while playing games.
Last night, I set all settings to 'Low' in Battlefield : Bad Company 2 and still it wasn't touching 40fps. At all settings max, it runs at 18-20 fps. How pathetic is that? And I know it is not running on onboard graphics, because if I set it so, the performance drop is immense. Now I would like to know how many other owners of 6121TX here are having this problem.