After the recent pre-orders of the Oculus Rift and HTC Vive went live. Both companies were kind enough to provide some tools to tell if your PC can handle VR. In the case of Oculus it just looked at your hardware specification and anything less than a GTX 970 then you failed.
In the case of Steam VR, it runs a version of the robot repair demo shown to the media over the last six months. The near 2GB download from Steam aims to test your system and is primarily testing your video card as my own results show below. The Steam VR test gives you sliding scale from "No chance your machine will die" to "Your rig is one sweet machine" (I may have interpreted the results a little here)
In my own case, I've been holding off on a new video card purchase in the hope something new will arrive around the same time as my Rift and Vive. Apparently my GTX 780 (getting old) sits somewhere on the scale "Your video card is middle aged and fat". My rig is newly built with an i7-5930 but my video card old and clearly the test is highly focused on video card.
Clearly if you have something similar to a GTX 780 then you're going to need to upgrade!