EcoAlert: Titan Supercomputer --Launches New Era for Climate-Change Analysis at 20,000 Trillion Calculations per Second
The U.S. Department of Energy’s (DOE) Oak Ridge National Laboratory (ORNL) has launched a new era of scientific supercomputing today with Titan, a system capable of more than 20,000 trillion calculations each second — or 20 petaflops — peak performance by employing a family of processors called graphic processing units (GPUs) first created for computer gaming. Titan will provide unprecedented computing power for research in energy, climate change, materials and other disciplines to enable scientific leadership.
The Cray XK7 system contains 18,688 nodes, with each holding a 16-core AMD Opteron 6274 processor and an NVIDIA Tesla K20 graphics processing unit (GPU) accelerator. Titan also has more than 700 terabytes of memory. The combination of central processing units (CPUs), the traditional foundation of high-performance computers, and more recent GPUs will allow Titan to occupy the same physical space as its Jaguar predecessor while using only marginally more electricity.
“One challenge in supercomputers today is power consumption,” said Jeff Nichols, associate laboratory director for computing and computational sciences. “Combining GPUs and CPUs in a single system requires less power than CPUs alone and is a responsible move toward lowering our carbon footprint.
Researchers have been preparing for Titan and its hybrid architecture for the past two years, with many ready to make the most of the system on day one. Among the flagship scientific applications on Titan:
Materials Science: The magnetic properties of materials hold the key to major advances in technology. The application WL-LSMS provides a nanoscale analysis of important materials such as steels, iron-nickel alloys and advanced permanent magnets that will help drive future electric motors and generators. Titan will allow researchers to improve the calculations of a material’s magnetic states as they vary by temperature.
“The order-of-magnitude increase in computational power available with Titan will allow us to investigate even more realistic models with better accuracy,” noted ORNL researcher and WL-LSMS developer Markus Eisenbach.
Combustion: The S3D application models the underlying turbulent combustion of fuels in an internal combustion engine. This line of research is critical to the American energy economy, given that three-quarters of the fossil fuel used in the United States goes to powering cars and trucks, which produce one-quarter of the country’s greenhouse gases.
Titan will allow researchers to model large-molecule hydrocarbon fuels such as the gasoline surrogate isooctane; commercially important oxygenated alcohols such as ethanol and butanol; and biofuel surrogates that blend methyl butanoate, methyl decanoate and n-heptane.
Nuclear Energy: Nuclear researchers use the Denovo application to, among other things, model the behavior of neutrons in a nuclear power reactor. America’s aging nuclear power plants provide about a fifth of the country’s electricity, and Denovo will help them extend their operating lives while ensuring safety. Titan will allow Denovo to simulate a fuel rod through one round of use in a reactor core in 13 hours; this job took 60 hours on the Jaguar system.
Climate Change: The Community Atmosphere Model-Spectral Element simulates long-term global climate. Improved atmospheric modeling under Titan will help researchers better understand future air quality as well as the effect of particles suspended in the air.
Using a grid of 14-kilometer cells, the new system will be able to simulate from one to five years per day of computing time, up from the three months or so that Jaguar was able to churn through in a day.
“As scientists are asked to answer not only whether the climate is changing but where and how, the workload for global climate models must grow dramatically,” noted CAM-SE team member Kate Evans of ORNL. “Titan will help us address the complexity that will be required in such models.”