Connecting multiple monitors for AMD Eyefinity technology couldn’t be simpler. There are four easy rules to remember:

The first two monitors can connect to the graphics card with any display output on your product: HDMI, VGA, DVI or DisplayPort.
The third (or greater) display must be connected to the graphics card via DisplayPort.

http://www.amd.com/us/products/technologies/amd-ey efinity-technology/how-to/Pages/faqs.aspx#products -support