ATI’s Evergreen cards brought multi-display gaming to the mainstream audience with its ability to power up to three monitors using only a single graphics card. With Northern Islands, AMD is naturally expanding the prowess of EyeFinity.
First and foremost AMD has upgraded the output connectors of their cards. The cards now boast the latest HDMI 1.4a ports, which have 3D output support and thus are fully capable of 3D Blu-ray playback on any display device supporting this HDMI standard. HD audio bitstreaming, which was already standard on Evergreen cards, will continue to feature on Northern Islands, and this will surely please the movie lovers, audiophiles and HTPC enthusiasts.
AMD has also upgraded the DisplayPort ports to version 1.2 and offers two of them. This new version has much higher throughput to support multiple displays from a single port and run them each at different resolutions; it even supports 3D output. The number of monitors that a single DisplayPort 1.2 port can drive is determined by the amount of available bandwidth, which in turn is dependent on the resolution that the display is running at. For example, a single DisplayPort can now drive up to four displays running at 1080p resolution via daisy-chaining or using a Multi-Stream Transport (MST) hub. If you up that resolution to 2560 x 1440, then a single DisplayPort 1.2 port has only sufficient bandwidth for two. And although it is possible for a single DisplayPort 1.2 to drive more than six monitors running at lower resolutions (such as 1366 x 768), AMD has limited the maximum number of supported displays to six (no matter what connectivity option is used), which should be more than sufficient.
Here are some examples of what's possible with the Radeon HD 6870:
One thing to note about the twin DVI ports on the Radeon HD 6870 is that only one of them is a dual-link capable- the other is only single-link. Though this wouldn’t matter to most people, but for those who intend or are running on dual 2560 x 1600 pixels resolution monitors, it’s something to take note. Fortunately, the DisplayPort adapters are available to support more of such outputs.