I think any of FX 83XX should be enough.
But here is official requirements
In a move to open up the Oculus Rift to a bigger part of the market, Oculus CEO Brendan Iribe announced at the Oculus Connect developer conference that the minimum PC requirements to support the Oculus Rift are being lowered.
The new minimum hardware requirements are as follows:
What is the best main board? I have a 8350 but am willing to upgrade. All the boards I seem to get have etronics usb. I did purchase a inateck pcie 3.0 but I still keep failing the usb test. Thanks for any advice you may have.