| Sponsors: | U.S. Department of Energy |
| Location: | Livermore Computing Complex |
| Architecture: | HPE Cray Shasta |
| Memory: | TBA |
| Storage: | TBA |
| Speed: | 1.742 exaFLOPS (Rmax) / 2.746 exaFLOPS (Rpeak) |
| Power: | 40 MW (Proj) |
| Os: | TOSS |
| Space: | TBA |
| Cost: | million (estimated cost) |
| Purpose: | Scientific research and development, stockpile stewardship[1] |
Hewlett Packard Enterprise El Capitan, is an exascale supercomputer, hosted at the Lawrence Livermore National Laboratory in Livermore, United States and becoming operational in 2024. It is based on the Cray EX Shasta architecture. El Capitan displaced Frontier as the world's fastest supercomputer in the 64th edition of the Top500 (Nov 2024). El Capitan is the third exascale system deployed by the US.
El Capitan uses a combined 11,039,616 CPU and GPU cores consisting of 43,808 AMD 4th Gen EPYC 24C "Genoa" 24 core 1.8 GHz CPUs (1,051,392 cores) and 43,808 AMD Instinct MI300A GPUs (9,988,224 cores). The MI300A consists of 24 Zen4 based CPU cores, and a CDNA3 based GPU integrated onto a single organic package, along with 128GB of HBM3 memory.[2]
The floor space and number of racks for El Capitan have not yet been disclosed.
Blades are interconnected by an HPE Slingshot 64-port switch that provides 12.8 terabits/second of bandwidth. Groups of blades are linked in a dragonfly topology with at most three hops between any two nodes. Cabling is either optical or copper, customized to minimize cable length. Total cabling runs 145km (90miles).
El Capitan uses an APU architecture, where the CPU and GPU share an internal on-chip coherent interconnect.
El Capitan was ordered as a part of the Department of Energy's CORAL-2 initiative, intended to replace Sierra, an IBM/NVIDIA machine deployed in 2018. LLNL partnered with HPE Cray and AMD to build the system.[3]
Three El Capitan prototypes – named rzVernal, Tioga, and Tenaya – themselves were powerful enough to be listed on the TOP500 supercomputer list in June, 2023.[4] rzVernal reached 4.1 petaflops.[5] In early July, the first components of El Capitan were installed at Lawrence Livermore, with complete installation expected by mid 2024.[6]