Crossroads (supercomputer)

Crossroads (supercomputer). Crossroads is a high-performance computing system developed for the National Nuclear Security Administration (NNSA) and deployed at Oak Ridge National Laboratory (ORNL). As part of the NNSA's Advanced Simulation and Computing (ASC) program, its primary mission is to support the Stockpile Stewardship Program, ensuring the safety, security, and reliability of the United States' nuclear deterrent without underground testing. The system represents a key collaboration between the United States Department of Energy, Hewlett Packard Enterprise (HPE), and Advanced Micro Devices (AMD).

Overview

Crossroads is a supercomputer engineered to run complex, three-dimensional, high-fidelity simulations critical for the Stockpile Stewardship Program. It is housed at the Oak Ridge Leadership Computing Facility (OLCF), a major center for computational science within the United States Department of Energy complex. The system serves as a successor to previous NNSA capability systems like Trinity at Los Alamos National Laboratory and is designed to tackle the most demanding workloads in computational physics, weapons science, and materials science. Its deployment underscores the ongoing commitment to maintaining a technological edge in predictive simulation for national security.

Hardware and architecture

The Crossroads system is built on the Hewlett Packard Enterprise Cray EX platform, a scalable supercomputer architecture known for its robust interconnect and efficient cooling. It is powered by next-generation AMD EPYC central processing units (CPUs) coupled with AMD Instinct graphics processing units (GPUs) in an accelerated compute design. This heterogeneous computing approach, utilizing both CPU and GPU resources, is optimized for the massive parallelism required by advanced simulation codes. The system features a high-performance Slingshot interconnect from Cray to facilitate rapid data movement between its many nodes, which is essential for large-scale scientific computing applications.

Development and deployment

The development of Crossroads was managed through a partnership between the National Nuclear Security Administration, Hewlett Packard Enterprise, and Advanced Micro Devices, under the auspices of the Advanced Simulation and Computing program. The system was installed at Oak Ridge National Laboratory in Tennessee, with acceptance testing and integration occurring through 2022. Its deployment followed a rigorous procurement and development cycle typical of major United States Department of Energy computing projects, aimed at delivering a capable platform for the Lawrence Livermore National Laboratory, Los Alamos National Laboratory, and Sandia National Laboratories user communities. The project leveraged expertise from the Oak Ridge Leadership Computing Facility in operating world-leading high-performance computing systems.

Performance and applications

Crossroads delivers a theoretical peak performance exceeding 40 petaFLOPS, placing it among the most powerful supercomputers dedicated to national security. Its computational power is primarily applied to running sophisticated simulation codes like xRage and Lagrangian hydrocodes, which model the extreme physics of nuclear weapon performance and aging. Applications extend to allied fields such as computational fluid dynamics, radiation transport, and the behavior of materials under conditions of high temperature and pressure. The system's performance enables scientists at the Nevada National Security Site and the national laboratories to conduct virtual experiments that were once only possible through physical testing.

Significance and impact

The deployment of Crossroads marks a significant advancement in the computational capabilities of the National Nuclear Security Administration's Stockpile Stewardship Program. By providing an order-of-magnitude increase in simulation fidelity over its predecessors, it enhances confidence in the assessments of the nuclear weapons stockpile. Furthermore, the technology developed for Crossroads, particularly its use of advanced AMD GPU accelerators and the HPE Cray EX architecture, influences the broader trajectory of high-performance computing. Its success informs future systems for both national security and open scientific research, contributing to the United States' leadership in exascale computing as exemplified by projects like Frontier at Oak Ridge National Laboratory. Category:Supercomputers Category:Oak Ridge National Laboratory Category:National Nuclear Security Administration Category:Advanced Micro Devices Category:Hewlett Packard Enterprise