APPLICATIONS
ORNL Cray supercomputer doubles performance
Science is the big winner as Oak Ridge National Laboratory's supercomputer has moved up in location and performance and is now the most powerful open scientific computing system in the world. The recent expansion of the Cray XT system doubles the performance of the computer, nicknamed Jaguar, which moved to the second floor to make room on the first floor of the National Center for Computational Sciences for a 1 petaflops system. The petaflops computer, capable of 1 quadrillion mathematical calculations per second, is scheduled for delivery in late 2008. 
"With this expansion the Department of Energy Leadership Computing Facility at the National Center for Computational Sciences reaches another milestone along the path to a petaflops," said Thomas Zacharia, associate lab director. "Scientists from around the nation will be better able to tackle challenges using increasingly complex simulations that will provide new insights in a host of disciplines." Work on doubling the size of the system began several weeks ago and was a substantial undertaking, involving 124 cabinets and 11,708 dual-core AMD Opteron processors. The system has a rating of 119 teraflops of peak performance (119 trillion mathematical calculations per second). On average, each cabinet houses 96 processors. The enhanced Jaguar also features 46 terabytes of memory and 750 terabytes of disk storage. Acceptance testing, which consists of running a number of science applications for many hours to put the machine through its paces, was completed last week, according to Buddy Bland, project director for the Leadership Computing Facility. "We are excited about the performance that we see for a number of scientific applications," Bland said. "For example, the upgraded Jaguar achieved 68 percent of the peak performance running a major materials code used for modeling semiconductors and storage devices, and we expect to achieve in excess of 80 teraflops sustained performance on the new system. "AORSA, a major fusion code, achieved sustained performance of 38 teraflops on the first ever run on the system, which is the fastest ever for this application. We expect the code to achieve in excess of 60 teraflops sustained performance." DOE's Leadership Computing Facility is on a path to reach 250 teraflops by late 2007 as dual-core processors will be replaced with AMD quad-core processors. The memory will be doubled and the operating system will migrate to a version of Linux on the computer nodes. As the largest computer in DOE's Office of Science, Jaguar is the major computing resource for the Innovative and Novel Computational Impact on Theory and Experiment, or INCITE, program. Earlier this year, the Office of Science awarded 70.7 million hours of processor time to be performed on Jaguar. The projects range from efforts to better understand core collapse of supernovae to improving the efficiency of catalytic processes directly involved in the synthesis of 20 percent of all industrial products. Within the DOE mission, catalysts feature prominently in cleaner and more efficient energy production. Among the numerous other INCITE research projects are several that will benefit the fusion energy community. One in particular is aimed at understanding and predicting the effects of high-power radio frequency waves on plasma stability, which is critical to developing fusion as an energy source. Another project focuses on determining how the ITER plasma can be heated using high-power radio frequency waves. The expansion is the second significant jump in the Cray's performance in the last seven months. While sheer power is important, a computer's ability to run programs vital to the scientific community has always been the focus for ORNL and Cray. "We are proud that ORNL chose Cray as its ongoing partner to provide leadership computing capabilities for science and industry," said Peter Ungaro, Cray president and chief executive officer. "The Cray XT4 system upgrade extends the system's productive life allowing ORNL to improve their total cost of ownership, a highly compelling capability we engineered into the Cray XT infrastructure. "ORNL users have made major advances using the Cray XT3 system and we are excited to see what new discoveries will be made with this substantially increased computing capability."
