Energy’s Forthcoming Nuclear Security-Focused Supercomputer Could Be Faster Than Originally Expected

El Capitan—the exascale supercomputer recently tapped by the Energy Department’s National Nuclear Security Administration to support the U.S. nuclear stockpile—will fully launch a little later than previously stated but is anticipated to be the fastest exascale-class supercomputer on Earth, reporters heard this week. 

The system, set to be housed at Lawrence Livermore National Laboratory, was originally unveiled in August when Energy announced it signed a $600 million contract with Cray Inc. to produce it. In late September, Hewlett Packard Enterprise, or HPE, acquired supercomputer leader Cray.

Officials from Lawrence Livermore, HPE and Advanced Micro Devices, Inc., or AMD, briefed reporters this week, highlighting new details about El Capitan’s components and forthcoming capabilities. 

Bronis de Supinski, chief technology officer for Livermore Computing at Lawrence Livermore, confirmed for the first time that AMD is the processor vendor slotted to provide El Capitan’s central processing units and graphics processing units, or CPUs and GPUs, and the architectures to support them. He said part of the reason that this key system information was left out of the first announcement was because Lawrence Livermore engaged in a late binding contractual vehicle that allowed officials to establish “an initial plan of record and then subsequently refine that and evaluate additional options that might become available” for the system. 

“So we did that and we were able to make significant improvements to the system through that process,” he said.

Though the original announcement indicated that the national lab would gain the exascale system in late 2022, de Supinski confirmed that El Capitan would likely not be fully accepted until some time in 2023. Still, El Capitan’s performance capabilities will enable it to operate at a potentially record-breaking speed of 2 exaflops. 

“Our previous announcement said that it would be greater than one and a half exaflop,” de Supinski said. “So this represents a significant increase in the expected performance of the system.”

The new anticipated performance record of 2 exaflops is an increase of more than 30% from initially projected estimates calculated seven months ago, officials noted, and that leap was made possible by the partnership between Energy, HPE and AMD. An exaflop entails the powerful capability of performing a quintillion mathematical calculations per second, so El Capitan will be able to perform 2,000,000,000,000,000,000 per second. To put this speed into perspective, the system is expected to operate at a speed that’s about 10 times faster than the fastest supercomputer on the planet today, and quicker than the fastest 200 supercomputers in the world combined, according to Steve Scott, HPE’s senior vice president, senior fellow and CTO for high-performance computing and artificial intelligence. 

“If everyone on Earth did a calculation every second, it would take eight years to do what El Capitan will do in a single second,” Scott said. “So that's a pretty stunning amount of computational power.” 

Lawrence Livermore also houses the hybrid supercomputer Sierra, which doesn’t perform at exascale, but holds the second spot on the top 500 list of the world's fastest supercomputers. El Capitan, officials noted, will operate at speeds 16 times faster than that. 

NNSA’s inherent mission is to advance national security through the military application of nuclear science, reduce global threats of nuclear proliferation and nuclear terrorism and protect America’s nuclear weapon stockpile. Nuclear weapon tests are internationally banned, so NNSA depends on complex supercomputing simulations to certify that the nation's nuclear stockpile is safe, secure, reliable and, as de Supinski put it, that “God forbid, if we should actually have to use it, that it will work as intended.” He added that the complexity of the simulation zone grows as the nuclear stockpile ages, so insiders need the ability to use larger and larger systems “to maintain the level of assurance that the nation really needs.”

The exceedingly high-performance capabilities that El Capitan is anticipated to offer will help NNSA meet that need—and it will even enable the nuclear agency to do those much needed 3D simulations on a regular basis. 

“Simulations that now require all, or a large portion, of Sierra will be able to be performed routinely, which means that we'll be able to have much greater statistical confidence in the results and that our models that we use for providing that certification will be more accurate,” de Supinski said. “So overall, we expect this system to have a very significant benefit to the nation's security.”