Look for "Solved" discussions. https://www.google.com/search?q=Dual+Monitor+Troubleshooting+-+Nvidia+GeForce+GTX650&ie=utf-8&oe=utf-8#q=Dual+Monitor+Troubleshooting+-+Nvidia+GeForce+GTX+650
I did check out dual link and this card does have that. http://www.geforce.com/hardware/desktop-gpus/geforce-gtx-650/specifications
Maybe the second port is just blown.
Hi there,
I have a Nvidia GeForce GTX 650 graphics card for which I'm trying to set-up a dual monitor display. This particular card has two dvi ports: a DVI-D and a DVI-I--as well as a VGA.
Monitor-wise, I bought both an Asus VG248QE and an Asus VS248H-P to hook up to it. When I try to plug both monitors into each port, both my Windows and my Nvidia command centers only recognize one monitor--which happens to be whichever is plugged into the DVI-D port. Both are connected using the default DVI cables that came in the boxes. When I switch the cables and monitors, my computer and graphics card still can only recognize the one plugged into the DVI-D port.
Any ideas as to what could be the problem? I've even tried plugging one monitor in through VGA and HDMI, but still the system only recognizes the monitor using that first DVI-D port. Do I need a converter cable?
Thanks so much!

Chowhound
Comic Vine
GameFAQs
GameSpot
Giant Bomb
TechRepublic