Here's a link to an engadget article just released today saying that the Occulus Rift is lowering it's minimum requirements to an i3 6100 and a gtx 960! This is incredible news as I thought I was going to have to buy a new CPU before I got a Rift, but I think with these new specs, my old i5 2500k still has some life left in her yet. Especially if I overclock it. (Just want to add that the i5 2500k might be the best hardware purchase I've ever made)
https://www.engadget.com/2016/10/06/you-don-t-need-a-ridiculous-pc-to-run-oculus-rift-anymore/
https://www.engadget.com/2016/10/06/you-don-t-need-a-ridiculous-pc-to-run-oculus-rift-anymore/