PC Perspective reports Valve is making efforts to bring virtual reality to a wider audience by lowering the system requirements. It appears the game publishers is experimenting with frame doubling or frame interpolation methods to allow you to get a good VR experience even if your GPU can only achieve 45fps instead of the 90fps that's usually recommended to create a smooth and effective immersion. Furthermore, the article also talks about adaptive quality, which involves techniques to turn down image quality selectively:
Vlachos also mentioned some other avenues that Valve could expand on to help improve performance. One of them is "adaptive quality", a feature we first saw discussed with the release of the Valve SteamVR Performance Test. This would allow the game to lower the image quality dynamically (texture detail, draw distance, etc.) based on hardware performance but might also include something called fixed foveated rendering. With FFR only the center of the image is rendered at maximum detail while the surrounding image runs at lower quality; the theory being that you are only focused on the center of the screen anyway and human vision blurs the periphery already. This is similar to NVIDIA's multi-res shading technology that is integrated into UE4 already, so I'm curious to see how this one might shape out.
These tricks enable Valve to run the Aperture VR test on a GeForce GTX 680 without dropping frames.