What does a theoretical model of the interaction of subatomic particles have to do with Elder Scrolls V: Skyrim? They both require a lot of computing power. More specifically, they require computer chips that process data in a spatial framework and make billions of calculations per second.
Enter the graphics processing unit (GPU), a specialized electronic circuit originally designed for video games like Elder Scrolls and now being used by physicists, engineers, and others in the hard sciences to undertake calculations at speeds and complexities previously unattainable. Claudio Rebbi, a physics professor at the College of Arts & Sciences, is one of these pioneering scientists.
Rebbi, along with Professor Richard Brower in the College of Engineering (ENG) Electrical & Computer Engineering and CAS Physics Departments, uses a cluster of 160 interconnected GPUs to power investigations into quantum physics, the study of the behavior of matter and energy at microscopic and subatomic levels. The GPU cluster, the largest on the East Coast, was donated to Boston University by the Hewlett-Packard Company and installed on campus in November 2012. Dubbed the BUDGE (Boston University Distributed GPU Environment), the array of new computers can perform 32 trillion—that is 32 million million—operations per second. By hooking up a central processing unit (CPU) to the GPUs, Rebbi and Brower are able to simulate the interactions of quarks, which combine to form protons and neutrons, and gluons, which help generate the force of attraction among quarks. Their findings about the behavior and properties of these subatomic particles support researchers at particle accelerators. The GPU-enabled data give them a much better chance of actually observing these particles in reality because they know how the particles behave.
“There are some aspects of quantum theory that can only be handled by computer simulation,” says Rebbi. “We literally create a small chunk of space-time in our computers, and we simulate the quantum fluctuations.”
“We literally create a small chunk of space-time in our computers.” —Claudio Rebbi
BU has been a leader in high-performance computing for over two decades. In 1990, Rebbi, along with other BU colleagues, established the Center for Computational Science. In recent years the center, which Rebbi led until last year, adopted GPU technology and spearheaded a national effort to develop computing code that can run on GPUs. Rebbi, Brower, and ENG Assistant Professor of Mechanical Engineering Lorena Barba were the main pioneers of GPU technology at BU.
BU’s history of innovative efforts in GPU computing convinced Hewlett-Packard to donate the GPU cluster last year—a $320,000 value. Having such technology at their fingertips will enable current and future CAS and College of Engineering researchers—in fields ranging from fluid dynamics to computational biology—to continue pushing the boundaries of our knowledge of the physical world.