A photo of the display wall running Google Earth.
A photo of the display wall running Google Earth.

The Visual Analytics Laboratory was begun in 2009 as a complement to the visual analytics research taking place in the Virtual Environments and Visualization section. We have constructed a few tiled-display clusters, the largest of which is described below. Other facilities include six-tile display workbenches powered by workstations with three graphics cards.

For more information, contact 5581web_info@nrl.navy.mil.

Building a Large Tiled-Display Cluster

Regardless of the resources available to a single workstation, cluster computing remains a simple means to theoretically multiply computational throughput. In the same way, individual displays or projectors can be combined to expand the visual real estate of system. A tileddisplay cluster is a combination of networked machines and multiple monitors. Tiled-display clusters allow researchers to employ these resources on a single large-scale visualization or series of visualizations. Applications include immersive virtual environments, presentation demonstrations, group collaborative views, and command-center views.

A photo of the wall, displaying a large-scale spherical panorama of the sky with marked objects.
A photo of the wall, displaying a large-scale spherical panorama of the sky with marked objects.

We endeavored to build the most advanced tiled-display cluster possible within a limited laboratory space. We decided on high-resolution desktop monitors over larger format, thin bezel displays so that we could get reasonably close to the displays and still see new detail. We chose 30-inch WQXGA desktop monitors as the tiles for our display wall. The end result was an 18 node cluster, with 15 nodes displaying to a 60-monitor, tiled-display matrix which spans three walls in a U-shape. The remaining nodes are used for auxiliary computation and coordination. The wall configuration uses a free-standing monitor-support structure and completely fills the available space. The cluster itself is stored in two 42U server racks in a separate room. Bundles of fifteen-meter DVI cables run through the ceiling from the racks to the displays in cable trays. Each rack-mount workstation houses two graphics cards (Nvidia Quadro FX 5800), and each graphics card in a display node renders two tiles in the wall, for a total of four displays per node.