Multiple Oculus Rifts from one video card?

Hi there Oculus VR community, I'm in the process of trying to develop a small walking demo for an upcoming event and it just suddenly struck me, I have 2 units but only one computer. Now I'm still new to all of this so I'm still learning but I wanted to know if it's possible to run 2 units off of one video card, now granted I am working with an older video card (Radeon HD 5770) but I have a new card on the way (Radeon r9 290x) the card has:

1 x HDMI
1 x DisplayPort
2 x DVI-D

Everything is still up in the air so I can adjust as needed but I was wondering if anyone has any experience with this, or any suggestions. Thanks a lot!