Retina Nvidia Control Panel Settings for Gaming
Here are my settings for BF3 - I also have a rMBP (15"). You can modify these settings under Manage 3D Settings in the NVIDIA Control Panel:



I leave everything else to default, except I also turn off Anisotropic Filtering.

For the above settings to take effect, the following setting must also be set under Adjust Image Settings with Preview:





Also, don't forget about BF3's settings. I use Realmware BF3 Settings Editor to edit settings out of the game.