Two dual DVI cards, but six outputs?

Question

I have two NVIDIA GeForce 9800 GT video cards. They run two monitors each:

But when I press the "Detect" button, I get this:

Is that an extra output per card? How do I make that work, by getting a DVI Y-adapter?

Answer 1

I'm not 100% certain on this, and correct me if I'm wrong, but I think the 9800 GT has the ability to display on 2 monitors at once - either 2xDVI or 1xDVI + 1xHDMI

You have 3 monitor connections, but only 2 of them can be used at any one time.

Answer 2

The third connector is a S-Video connector, you can activate it by connecting a S-video cable. Although I believe the 9xxx series cards are only capable of driving two displays per GPU. I can confirm this is the case with the 7950GT as well as the 8800GT I should have a 9800gt laying around to test 3 displays if you want.

EDIT: Matt Jenkins points out (below) that it is not actually S-video, it is mini-DIN which are fully compatible with S-video, they just provide increase functionality:

This is a non standard 7-pin mini-DIN connectors (this variant is called "7P"). These are used on computer equipment (PCs). A 7-pin socket accepts and is pin compatible with standard 4-pin S-video plug.[5] The three extra may be used to supply composite (CVBS) or an RGB or YPbPr video signal, or an I²C interface. The pin out usage varies between manufacturers.[5] In some implementations, the remaining pin needs to be grounded to enable the composite output (or disable the S-video output on some of those implementations).

Answer 3

There is clearly a third output on the card:

However I can't find anything on the site that indicates what it might be - it looks like it could be S-Video but (as Matt points out) is actually a 7 pin mini DIN socket.