Using one of the most powerful supercomputers in the world, Purdue researchers have started studying the next generation of computer chips before they are even built.

In December 2008, the Department of Energy awarded electrical and computer engineering Professor Gerhard Klimeck and colleagues 5 million computer hours under its INCITE (for Innovative and Novel Computational Impact on Theory and Experiment) program.

The program, open to all scientific researchers and research organizations, including industry, is for computationally intensive research projects of large scale that can make high-impact scientific advances through a major allocation of computer time, resources and data storage, according to DOE Office of Science officials.

Klimeck’s was one of 25 projects — competitively selected for technical readiness and scientific merit — that will advance research in key areas such as astrophysics, climate change, new materials, energy production and biology for applications ranging from designing quieter cars and improving commercial aircraft design to developing nanomaterials and simulating earthquakes, said a DOE press release announcing the awards in December 2008.

“From understanding the makeup of our universe to protecting the quality of life here on Earth, the computational science now possible using DOE’s supercomputers touches all of our lives,” said DOE undersecretary for science Raymond Orbach. “By dedicating time on these supercomputers to carefully selected projects, we are advancing scientific research in ways we could barely envision 10 years ago, improving our national competitiveness.”

Klimeck’s Purdue lab used its allocation for atomic-level modeling and simulation — in effect, virtual nanotechnology engineering — of tiny transistors. The work is designed to address the increasing difficulty of designing microprocessors and other devices central to the electronics age at a time when their components have reached and are dipping into the nanoscale. A nanometer is a billionth of a meter — about 50,000 times smaller than a human hair is round.

Klimeck said the research could help in shifting nanotechnology from the realm of scientific discovery to practical application.

“The availability of such large-scale machines and the codes that can utilize them enables us to move nano science to nano engineering,” he said.

The Purdue researchers’ goal is understanding design implications of advanced transistors at the nanometer scale. To do that, they modeled and simulated tens of thousands to millions of atoms in the devices using nano-electronic modeling software such as OMEN — developed by Purdue research professor Mathieu Luisier — and NEMO3D, developed by Klimeck, associate director for technologies at the Network for Computational Nanotechnology at Purdue.

Capturing the actions and interactions of that many atoms takes massive computing power. With the INCITE award, the Purdue researchers were able to draw on the Jaguar supercomputer at Oak Ridge National Laboratory in Tennessee, which, as of November 2008, had a peak performance in excess of a petaflop — or a quadrillion mathematical calculations per second. It would take the Earth’s entire population — more than 6 billion people — 460 years working with hand calculators to accomplish what the machine can do in a day.

The system — No. 2 on the list of the world’s top 500 supercomputers for science released in November 2008 — includes more than 180,000 processors, kind of the brain of a computer. Klimeck said access to Jaguar allowed large-scale simulations the researchers couldn’t perform on other, less powerful machines.

Getting software to make efficient use of all those processors is a challenge, but Klimeck and Luisier already have been able to “scale” OMEN and NEMO3D for thousands of processors — more than 59,000 in the case of OMEN. They use a variety of computational resources, including Purdue’s Steele cluster, which also made the top 500 supercomputers list. With more than 7,100 processors, Steele is operated by the Rosen Center for Advanced Computing, the research and discovery arm of ITaP, Purdue University's central information technology organization.

Writer: Greg Kline, science and technology writer, ITaP, (765) 494-8167, gkline@purdue.edu

Source: Gerhard Klimeck, (765) 494-9212, gekco@purdue.edu

More information:
Versions of NEMO3D and OMEN are available for open public use at the web-based simulation portal in end-to-end online tools Quantum Dot Lab, Bandstructure Lab and OMEN nanowire. Quantum Dot Lab has been employed by more than 1,600 users and Bandstructure Lab by more than 2,000 users, while OMEN nanowire has just been released. In all, nanoHUB.org is serving more than 87,000 users annually in 172 countries with online simulation tools, nanotechnology tutorials and more. Click here for more information on NEMO3D and OMEN.

NanoHUB is based on the Purdue-developed HUBzero technology — an elegant, easy-to-use system for creating online communities where educators and researchers can share ideas, tools, computational resources and data.

About the image:
A 3-D volume rendering of electron density in a nanowire. The “thicker” parts are the source (left) and the drain (right). The central region shows the gate (the external switch) that modulates the current flow through the structure. Animated versions with additional information can be found here.

Last updated: Sept. 18, 2009

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