CORAL Collaboration logo

What is CORAL?

CORAL is a first-of-its-kind U.S. Department of Energy (DOE) collaboration between the National Nuclear Security Administration’s (NNSA’s) ASC Program and the Office of Science’s Advanced Scientific Computing Research program (ASCR) that culminated in three ultra-high performance supercomputers at Lawrence Livermore, Oak Ridge, and Argonne national laboratories. The systems, delivered in the 2017 timeframe, are used for the most demanding scientific and national security simulation and modeling applications, and enable continued U.S. leadership in computing. The Livermore system resulting from CORAL is named Sierra.

CORAL is the next major phase in the U.S. Department of Energy’s scientific computing roadmap and path to exascale computing. The procurements resulting from CORAL are influencing the modernization of future generations of computing throughout the NNSA complex.

Sierra logo

What is Sierra?

Sierra is the current advanced technology high performance computing system for NNSA’s ASC Program, and was sited at Lawrence Livermore in 2017. Purchased through the CORAL request for proposal process, Sierra provides over five times the sustained scalable science performance of its predecessor, Sequoia.

Sierra provides computational resources that are essential for nuclear weapon scientists to fulfill the stockpile stewardship mission through simulation in lieu of underground testing. Modern simulations on powerful computing systems are key to supporting the annual assessment of all stockpile systems, resolving significant finding investigations (SFIs), accomplishing upcoming life extension programs (LEPs) with computationally taxing advanced safety and surety features, and for supporting qualification of hostile environments, safety calculations of abnormal environments, and gravity and reentry simulations.

What is Sierra’s architecture?

Sierra provides over five times Sequoia's workload performance with a 125 petaflop/s peak. The Sierra system includes compute nodes (POWER9 Architecture Processor, NVIDIA Volta GPUs, NVMe-comaptible PCIe 800 GB SSD, greater than 512 GB DDR4 + HBM, and coherent shared memory) and compute racks (standard 19-inch with warm-water cooling). The compute system includes 1.38 petabytes of memory, provides 125 petaflop/s peak performance, and uses 11 MW of power. The Global Parallel File System has 120 PB usable storage and 1.0 TB/s bandwidth.

How is Sierra used?

Sierra serves the NNSA’s ASC program to ensure the safety, security, and effectiveness of the nation’s nuclear deterrent without testing. Simulation is the integrating element of the science and engineering-based program to maintain the nation’s aging nuclear stockpile. Scientists and engineers in NNSA’s Advanced Simulation and Computing (ASC) program use Sierra to assess the performance of integrated weapon systems as well as for science and engineering calculations. Key scientific areas include: materials modeling problems; turbulent flow and instabilities in such flows; and so-called laser plasma calculations, necessary to assess and predict the performance of the National Ignition Facility (NIF) in its support of the program. This work has important implications for other national security concerns, including nonproliferation and counterterrorism. The new capabilities developed on Sierra also are being applied to the study of other global and national challenges such as energy, climate change, and medicine.

Where can I find more information?