The Department of Energy (DOE), National Nuclear Security Administration (NNSA) and Lawrence Livermore National Laboratory (LLNL) signed contracts with Cray Inc. to build the NNSA’s first exascale supercomputer, named El Capitan.

El Capitan will have a peak performance of more than 1.5 exaflops (1.5 quintillion calculations per second) and an anticipated delivery in late 2022. The total contract award is valued at $600 million.

The supercomputer is intended to run national nuclear security applications. Depending on the application, El Capitan could run roughly 10 times faster on average than LLNL’s Sierra system, currently one of the world’s most powerful supercomputers. El Capitan is expected to serve the needs of NNSA’s laboratory community, which includes LLNL, Los Alamos National Laboratory and Sandia National Laboratories.

El Capitan will be the DOE’s third exascale-class supercomputer, following Argonne National Laboratory’s Aurora and Oak Ridge National Laboratory’s Frontier system. All three DOE supercomputers will have been built by Cray.

Developed as part of the second phase of the collaboration of Oak Ridge, Argonne and Livermore (CORAL-2) procurement, El Capitan will make assessments necessary for addressing threats to national security, and other purposes such as nonproliferation and nuclear counterterrorism.

Exascale performance will be delivered by a heterogeneous central processing unit (CPU)/graphical processing unit (GPU) architecture. This architecture will allow researchers to run exploratory 3D simulations at resolutions that are currently unobtainable, and ensembles of 3D calculations at resolutions that are difficult, time-consuming or even impossible using today’s supercomputers. 3D simulations are becoming essential to meet the demands of the NNSA life extension programs and address nuclear weapon aging issues for which researchers have no nuclear test data.

El Capitan will be built on Cray’s Shasta supercomputing architecture and will be comprised of Shasta compute nodes and a future generation of ClusterStor storage. This architecture will be connected with Cray’s Slingshot high-speed interconnect. The Shasta hardware and software architecture can accommodate a variety of processors and accelerators. The platform also will use Cray’s system and analytics software stack, which will deliver scalability and flexibility needed for exascale computing. It also will enable the converged use of modeling, simulation and AI in support of the lab’s research missions.