The minimum requirements are:
The Stereoscopic checkbox in the Player Settings is strictly for DirectX 11.1’s stereoscopic 3d support. It doesn’t currently use AMD’s quad buffer extension. Make sure that this sample works on your machine. Stereo support works both in fullscreen and windowed mode.
When you launch the game, hold shift to bring up the resolution dialog. There will be a checkbox in the resolution dialog for Stereo3D if a capable display is detected. Regarding the API, there are a few options on Camera: stereoEnabled, stereoSeparation, stereoConvergence. Use these to tweak the effect. You will need only one camera in the scene, the rendering of the two eyes is handled by those parameters.
Note that this checkbox is not for VR headsets.
Note: Currently, setting Unity to render in linear color space breaks stereoscopic rendering. This appears to be a Direct3D limitation. It also appears that the
camera.stereoconvergence param has no effect at all if you have some realtime shadows enabled (in forward rendering). In Deferred Lighting, you will get some shadows, but insconsistent between left & right eye.