Q: How to configure ATI Eye Infinity for three monitors

A:
This affects only the Video Card: ATI 58XX series

Please see the ATI website for instructions on how to configure and use ATI Eye Infinity Technology.

Setup:
To use a three monitor EYE Infinity configuration requires both DVI ports and the Display Port. If the monitor does not have a Display Port, then a display port adapter may be used. To configure the video card with three monitors, an Active Display Port to DVI port adapter must be used. A passive Display Port to DVI adapter will allow video pass-through, but will not work in a three monitor ATI Eye Infinity configuration.

Please see this list on the ATI website for a list of approved Active Display Port dongles.
http://support.amd.com/us/eyefinity/Pages/eyefinity-dongles.aspx