# Introduction

## About Merlin6 GPU cluster

### Introduction

Merlin6 was a the official PSI Local HPC cluster for development and
mission-critical applications that has been built in 2019. It replaced
the Merlin5 cluster.

Merlin6 was designed to be extensible, so was technically possible to add
more compute nodes and cluster storage without significant increase of
the costs of the manpower and the operations.

Merlin6 was mostly based on **CPU** resources, but also contained a small amount
of **GPU**-based resources which are mostly used by the BIO experiments.

### Slurm 'gmerlin6'

THe **GPU nodes** have a dedicated **Slurm** cluster, called **`gmerlin6`**.

This cluster contains the same shared storage resources (`/data/user`, `/data/project`, `/shared-scracth`, `/afs`, `/psi/home`)
which are present in the Merlin6 Slurm CPU cluster. The Slurm `gmerlin6` cluster is maintainted
independently to ease access for the users and keep independent user accounting.

## Merlin6 Architecture

### Merlin6 Cluster Architecture Diagram

The following image shows the Merlin6 cluster architecture diagram:

![Merlin6 Architecture Diagram](../images/merlinschema3.png)

### Merlin6 Slurm Cluster Architecture Design

The following image shows the Slurm architecture design for the Merlin6 clusters:

![Merlin6 Slurm Architecture Design](../images/merlin-slurm-architecture.png)