One of the hurdles for VR is that the performance requirements are far higher than for a typical game.
When a system's average frame rate is below the target frame rate for the test, it means the system is not strictly VR-ready for that level of VR content. However, VR headsets will use clever techniques to compensate for the missed frames. In many cases, these techniques are very effective at providing a good-quality VR experience for the user by covering up missed frames.
When a system falls short of the benchmark's target frame rate, we highly recommend trying Experience mode with an HMD for yourself. You may find that, even though the rendering frame rate is below the target, the actual experience with a headset is still comfortable and enjoyable.
This is especially the case for systems with the recently announced, lower minimum hardware requirements for the Oculus Rift. These systems cannot render the Orange Room benchmark at 90 FPS on an HMD. Instead, they rely on a technique called Asynchronous SpaceWarp (ASW) in the Oculus Runtime.
"The Rift operates at 90 Hz. When an application fails to submit frames at 90 Hz, the Rift runtime drops the application down to 45 Hz with ASW providing each intermediate frame. ASW applies animation detection, camera translation, and head translation to previous frames in order to predict the next frame. As a result, motion is smoothed and applications can run on lower performance hardware."