El Capitan
Lawrence Livermore National Laboratory runs El Capitan for NNSA, serving Livermore, Los Alamos and Sandia with the 3D simulations that certify the safety, security and reliability of the US nuclear stockpile without testing.
What it runs and how to get time
From the operator- Used for What the operator says the system is used for: science domains, missions or workloads. Taken from the operator, its funder or the system vendor, not from TOP500.
- NNSA Stockpile Stewardship: high-resolution 3D weapons simulation for Livermore, Los Alamos and Sandia, plus AI workflows for national security 5
- How to get time How researchers or customers get time on the system, naming the allocation programme where the operator states one.
- Internal use only by the NNSA tri-labs under the ASC program; runs above 4,150 nodes need an ASC Dedicated Application Time (DAT) slot 4
- Cooling Cooling design stated by the operator or supplier.
- Direct liquid cooling with water warmed to about 85 F; heat rejected by evaporation at the ECFM cooling towers, ~400 kW per rack 6
- Power design Facility power, energy supply or heat reuse as stated by the operator. Not the benchmark power in the Power column.
- Peak power under 35 MW; ECFM project raised the computing floor from 45 MW to 85 MW and cooling from 10,000 to 28,000 tons 7
- Facility Building, data centre or campus that houses the system, as described by the operator.
- Livermore Computing Center at Lawrence Livermore National Laboratory, Livermore, California 9
- Status Operating status, filled only when the operator states it.
- Limited availability 4
Benchmark and hardware
Source per value- Rank Position in the TOP500 edition named in the Edition column. Historic systems keep the rank of the edition where they last appeared.
- 2 1
- Rmax PFLOP/s Measured double-precision LINPACK (HPL) performance of the listed configuration. Older TFLOP/s and GFLOP/s figures are converted to PFLOP/s.
- 1,809 1
- Rpeak PFLOP/s Theoretical peak double-precision performance of the listed configuration. This is not AI or mixed-precision throughput.
- 2,821.1 1
- HPL efficiency % Rmax divided by Rpeak: the share of theoretical peak the system delivered on LINPACK. Computed from the two sourced figures.
- 64.1 1
- Power kW Power reported for the benchmark run. Measurement boundaries vary by site; this is not facility power, TDP or cooling capacity. Empty when the system does not report it.
- 29,685 1
- Efficiency GFLOP/s per W Rmax per watt of reported benchmark power, computed from the two sourced figures (GFLOP/s per W). Empty when power is not reported.
- 60.94 1
- Site Host or operator named by TOP500 for the installation.
- DOE/NNSA/LLNL 1
- Country Country or region reported by TOP500 for the site.
- United States 1
- City Site city as reported by TOP500 or the operator. It can be the operator address rather than the machine room.
- Livermore 3
- Region World region of the installation country (grouping applied by this site).
- Americas 1
- Vendor Manufacturer or system supplier exactly as submitted to TOP500.
- HPE 1
- Vendor group Supplier grouped for filtering. Bull is the Eviden/Atos line; Other covers single-system suppliers.
- HPE 1
- System model Hardware platform in the cited TOP500 edition.
- HPE Cray EX255a 1
- Processor CPU description in the cited TOP500 edition; clock and core count refer to the processor model.
- AMD 4th Gen EPYC 24C 1.8GHz 1
- Accelerator Accelerator model listed for the system. Empty when TOP500 lists none.
- AMD Instinct MI300A 1
- Accelerator vendor Maker of the accelerator. None listed means TOP500 names no accelerator for the system.
- AMD 1
- Interconnect Network fabric exactly as listed in the cited TOP500 edition.
- Slingshot-11 1
- Fabric Interconnect family derived from the listed interconnect (grouping applied by this site).
- Slingshot 1
- Cores cores Total cores submitted to TOP500, including accelerator cores where TOP500 counts them. Not a CPU-only count and not a CUDA-core count.
- 11,340,000 1
- Installed Installation year reported in the TOP500 system record. Not necessarily the year of production acceptance.
- 2024 2
- Edition TOP500 edition (YYYY-MM) that supplies the ranking and benchmark data. A historic edition does not assert current operating status.
- 2026-06 1
- OS Operating system from the TOP500 system record.
- TOSS 2
- TOP500 record Link to the TOP500 database record for this exact submission.
- https://www.top500.org/system/180307/ 2
- Nodes nodes Compute node count as described by the operator. It can exceed the nodes used in the benchmark run.
- 11,424 4
- Accelerators per node per node Accelerator packages or superchips per node, as the operator describes them.
- 4 4
- Scheduler Job scheduler software reported by the operator.
- Flux 4
Sources
- TOP500 list, June 2026 accessed 2026-11-11
- TOP500 system record accessed 2026-11-11
- TOP500 site record accessed 2026-11-11
- hpc.llnl.gov (operator page) accessed 2026-11-11
- NNSA and Livermore Lab achieve milestone with El Capitan, the world's fastest supercomputer accessed 2026-11-11
- Meet the machines that matter: How El Capitan keeps its cool accessed 2026-11-11
- LLNL El Capitan Fact Sheet accessed 2026-11-11
- Powering up: LLNL prepares for exascale with massive energy and water upgrade accessed 2026-11-11
- NNSA Completes Lawrence Livermore National Laboratory Exascale Computing Facility Modernization Project accessed 2026-11-11