Oculus team is working hard to update their oculus with the Asynchronus Spacewarp algorithm, it is a frame-rate smoothing technique to almost halves the CPU and GPU time required to produce nearly same output from the same content, by this it will enables users to run Oculus Rift on a lower specification hardware. Previously you need expensive PC to make the VR games work, which oculus team wants to change this.
The more capable the machine is, the less likely it is to need ASW. ASW and its scene extrapolation is activated only when the application cannot maintain the nominal frame rate of the VR display. This means if you built a top-of-the-line machine, then you may never see ASW in action.
The hardware requirements for ASW are modest. This functionality has been enabled on all current-generation AMD GPUs (RX 400 series) and previous- or current-generation Nvidia GPUs (GTX 900 or 1000 series).
Although, Oculus team also noted developer to still optimise their games for smooth 90fps gameplay and the players should aim for the recommended specs in any event. If you want to read more about Asynchronous Spacewarp (ASW) see their official announce page (https://developer.oculus.com/blog/asynchronous-spacewarp/)