SCIENCE

CHAMPAIGN, IL -- The largest high-resolution, scalable display wall in academia is now in use at the National Center for Supercomputing Applications (NCSA) at the University of Illinois at Urbana-Champaign. The wall gives scientists the opportunity to visualize their research data in more detail than ever before possible. The 9-foot-high, 12-foot-wide screen can project images more than 20 times better than the typical computer monitor. The display surface--a screen divided into 20 sections--can display images of 4,096 x 3,840 pixels either as one large, high-resolution image or as several side-by-side images and information nodes. A 20-node Linux PC cluster powers the display wall, with each node consisting of a dual processor, 550 MHz HP Kayak machine equipped with a GeForce2 graphics accelerator card. The processors in the cluster communicate using Myricom's Myrinet and are connected to 20 NEC VT540 projectors arranged in a matrix of four across and five high. Although it is already the largest display wall in an academic setting, the wall is only half complete. When completed, the wall will be the largest high-resolution display wall anywhere, with a resolution of 8,096 pixels across and 3,840 pixels high on an 18-foot-wide screen.. It will be powered by a 40-node Linux cluster and connected to 40 video projectors. The completed wall will be operational by early 2002. "This display wall is a powerful new tool for science," said Dan Reed, director of NCSA and the National Computational Science Alliance (Alliance). "It builds on the power of Linux clusters and open source software, taking the art and science of scientific visualization to a new level. The screen is large enough to accommodate a small research team working together and the resolution is so high that it becomes possible to visualize large-scale datasets and imagery in their entirety." The display wall will be a welcome research tool for a wide range of scientists, including radio astronomers who study data collected by radio telescopes and compute images of such high resolution that they have yet to view them in their full detail. Researchers who study the formation of severe storms plan to use the wall for high-resolution simulations derived from satellite images. Medical imaging and geophysical applications could also benefit from the wall's ability to resolve detail never before possible in computer simulations. The new display wall combines cutting-edge technologies and new design ideas developed at NCSA. The wall's ability to tile images into one seamless image is a process that requires the projectors to be precisely aligned. NCSA's Rob Stein and Albert Khakshour designed a new frame system and projector positioner that allows for precise control over alignment. The frame and positioners are built from commercially available stock, and each projector is attached to its own positioner and mounted to an upright frame. "Assembling the full complement of 20 positioners was a group effort," said Polly Baker, director of NCSA's Data Mining and Visualization division and leader of the effort to build the wall. "It took our team about six hours to build the positioners, attach the projectors, and mount the units to the frame. And through the Display Wall-in-a-Box initiative, we're providing the information so that other sites can build and use their own display walls." Display Wall-in-a-Box is an Alliance effort to make it simpler and less expensive to offer high-end display capabilities on top of Linux clusters. The Alliance's scalable display wall software package, available on CD and through the Web, includes wall construction information, a software toolkit of utilities and applications, descriptions of existing Alliance walls, and guidelines and checklists of features to consider when evaluating new models of projectors and graphics cards. For more information on the new NCSA scalable display wall and on Display Wall-in-a-Box, see www.ncsa.uiuc.edu/TechFocus/Deployment/DBox/