IF you read through the Eyefinity technical brief you will see on page 8:http://www.amd.com/us/Documents/ATI_Eyefinity_Technology_Brief.pdf
"If only one or two DVI/HDMI monitors are attached through a DisplayPort connector, then only simple
passive adapters are required. With a passive adapter the GPU outputs the display signal required for
the monitor with no conversion occurring within the adapter itself."