As Whirligig play's media files it isn't the player that affects the playback speed but the video file you wish to run. As long as your system meets the requirements for the Oculus Rift then it should work fine. The required system is given below.
A couple of notes regarding this though. Firstly the player is made with the latest version of Unity3D and because of this requires the latest Oculus Rift runtime to be installed which is currently 0.8.0. It won't work with any runtime earlier than 0.8.0.
There is a version of the player built with an earlier version of Unity, Unity3D 5.1 which should work with the runtime 0.7.0 and may also play back smoother on low end systems. However this isn't the latest version and is only provided to give people who are having real issues the opportunity to try an earlier version.
Runtime Version : 0.8.0 or above.
Operating system : Windows PC running windows 7 or later.
GPU : Hardware (Laptop or onboard gpu's aren't support)