Dual monitor question - GTX 660

[respawn]

Hello, I just built a new rig that includes a MSI GTX 660 GPU.
I was running my current monitors (two) on my old machine with a four year old Geforce card. The new card has the two dvi outputs but the one on the bottom is missing the four holes around the horizontal pin so I cant plug it in. What am I missing? My old card has both dvi ports and they look exactly the same. If I want to use dual monitors on my new card, am I forced to use the HDMI port as one? What is the second DVI port for? Only SLI?

I am so confused.

 

[Aikouka]

Those four pins (really five) are for analog data, which aren't needed for a DVI-to-DVI setup. You can see more about it here:

http://en.wikipedia.org/wiki/DVI_connector

EDIT:

This really old Anandtech article talks about it too:
http://www.anandtech.com/show/869/3