# LUMI

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## What is LUMI?

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LUMI is the fastest supercomputer in Europe. It's an HPE Cray EX supercomputer consisting of several hardware partitions targeted different use cases: 

- 2560 GPU-based nodes ([**LUMI-G**](https://docs.lumi-supercomputer.eu/hardware/lumig/)), each node with one 64 core AMD Trento CPU and four AMD MI250X GPUs.
- 1536 dual-socket CPU nodes [**LUMI-C**](https://docs.lumi-supercomputer.eu/hardware/lumic/) with 64-core 3rd-generation AMD EPYC™ CPUs, and between 256 GB and 1024 GB of memory. 
- large memory GPU nodes [**LUMI-D**](https://docs.lumi-supercomputer.eu/hardware/lumid/), with a total of 32 TB of memory in the partition for data analytics and visualisation. 
- Main storage - [**LUMI-P**](https://docs.lumi-supercomputer.eu/storage/parallel-filesystems/lumip/) has 4 independent Lustre file systems with 20 PB and an aggregate bandwidth of 240 GB/s each. Each Lustre file system is composed of 1 MDS (metadata server) and 32 Object Storage Targets (OSTs).
- Flash storage - [**LUMI-F**](https://docs.lumi-supercomputer.eu/hardware/lumif/) has Lustre file system with a storage capacity of 8 PB and an aggregate bandwidth of 1 740 GB/s.
- Object store -  [**LUMI-O**](https://docs.lumi-supercomputer.eu/storage/lumio/) provides 30 PB storage.
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More  about LUMI system architecture can be found in [overview](https://docs.lumi-supercomputer.eu/hardware/) and [LUMI’s full system architecture](https://www.lumi-supercomputer.eu/lumis-full-system-architecture-revealed/). 


LUMI uses Slurm as job scheduler and resource manager. Slurm partitions can be allocated by node or by resources. More about partitions can be found [here](https://docs.lumi-supercomputer.eu/runjobs/scheduled-jobs/partitions/).


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## Why LUMI?

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There are several reasons to choose LUMI instead of HPC:

- if job is run using GPUs
- if job needs large memory
- if queue on HPC is too long
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## Getting started

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###  - [How to get access to LUMI](lumi/start.md)
###  - [Software](lumi/software.md)
###  - [Examples of jobs and slurm scripts](lumi/examples.md)
###  - [Billing](https://hpc.pages.taltech.ee/user-guides/index.html#billing)

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