# Lassen

> supercomputer

**Wikidata**: [Q74555395](https://www.wikidata.org/wiki/Q74555395)  
**Source**: https://4ort.xyz/entity/lassen

## Summary
Lassen is a supercomputer located at Lawrence Livermore National Laboratory in the United States. It was built by IBM and Nvidia and ranked 72nd on the TOP500 list as of November 2024.

## Key Facts
- Lassen is an IBM Power System AC922 supercomputer that began operation in 2018
- It uses IBM POWER9 CPUs with 22 cores running at 3.1 GHz and NVIDIA Tesla V100 GPUs
- The system achieved 18.20 petaflops Rmax performance and 23.05 petaflops Rpeak performance in June 2019
- Lassen contains 288,288 processor cores and uses Mellanox InfiniBand EDR interconnect
- It is operated by the United States Department of Energy, National Nuclear Security Administration, and Lawrence Livermore National Laboratory

## FAQs
### Q: What type of supercomputer is Lassen?
A: Lassen is an IBM Power System AC922 supercomputer that uses IBM POWER9 CPUs and NVIDIA Tesla V100 GPUs. It was designed for high-performance computing tasks and ranked among the world's top supercomputers when it was built.

### Q: Who operates Lassen and where is it located?
A: Lassen is operated by the United States Department of Energy, National Nuclear Security Administration, and Lawrence Livermore National Laboratory. It is physically located at Lawrence Livermore National Laboratory in California.

### Q: What are Lassen's key technical specifications?
A: Lassen features IBM POWER9 22-core processors running at 3.1 GHz, NVIDIA Tesla V100 GPUs, Mellanox InfiniBand EDR interconnect, and contains 288,288 processor cores total. It achieved 18.20 petaflops Rmax performance.

## Why It Matters
Lassen represents a significant advancement in supercomputing capabilities for scientific research and national security applications. As part of the United States' high-performance computing infrastructure, it enables complex simulations and data analysis that would be impossible on conventional computing systems. The system's architecture, combining IBM's POWER9 processors with NVIDIA's GPU technology, demonstrates the effectiveness of heterogeneous computing approaches for tackling computationally intensive problems. Lassen's capabilities support critical research in areas such as nuclear security, climate modeling, and materials science, making it an essential tool for maintaining technological leadership in scientific computing.

## Notable For
- Ranked 10th on the TOP500 list in June 2019 and 72nd in November 2024
- Achieved 18.20 petaflops Rmax performance in June 2019
- Uses advanced IBM POWER9 CPU and NVIDIA Tesla V100 GPU architecture
- Contains 288,288 processor cores for massive parallel computing
- Operated by Lawrence Livermore National Laboratory for Department of Energy research

## Body
### Technical Architecture
Lassen is built on the IBM Power System AC922 platform, featuring IBM POWER9 CPUs with 22 cores each running at 3.1 GHz. The system incorporates NVIDIA Tesla V100 GPUs for accelerated computing tasks. The interconnect infrastructure uses Mellanox InfiniBand EDR technology to provide high-bandwidth, low-latency communication between nodes.

### Performance Metrics
The supercomputer achieved significant performance milestones since its inception. In June 2019, Lassen reached 18.20 petaflops Rmax (maximum measured performance) and 23.05 petaflops Rpeak (theoretical peak performance). Earlier in November 2018, it achieved 15.43 petaflops Rmax and 19.90 petaflops Rpeak. The system contains a total of 5,059,584 processor cores across its architecture.

### Development and Operation
Lassen was developed through a collaboration between IBM, Nvidia, and Mellanox Technologies. The system began operation in 2018 and is specifically designed to support research activities at Lawrence Livermore National Laboratory. It is operated under the auspices of the United States Department of Energy and the National Nuclear Security Administration, focusing on applications that require extreme computational power for scientific and security-related research.

## References

1. [Source](https://top500.org/system/179567/)