Eyefinity. It's a feature in all of AMD's new 5800-series and 5700-series GPUs which enables the use of three monitors on a single video card. Unfortunately, it's not as easy as just plugging in three different monitors into any of the four available display ports. Eyefinity requires the use of the two dual-DVI ports plus a single DisplayPort-out port. And you know how rare DisplayPort is found on monitors these days.
To eliminate this hindrance, Sapphire has introduced an active DisplayPort-to-DVI adapter, so you can use a third monitor via dual-link DVI instead of DisplayPort for Eyefinity. It will cost around $60-70 if Nordic Hardware isn't mistaken, but it's a lot cheaper than having to buy an entirely new monitor with a DisplayPort connector.
Source: [Nordic Hardware]
