Hardware
========

The Bora HPC cluster consists of computing services and storage service. All servers in the HPC environment are based on Linux operating systems, distribution Rocky Linux 8.9.

A cluster is a collection of computing nodes connected by a communication network.

.. image:: cluster.svg

Three kinds of computing nodes are available on Bora:
   
- **CPU node**: multiple CPU cores
- **FAT node**: multiple CPU cores + large amount of RAM
- **GPU node**: multiple CPU cores + at least one GPU

Computing nodes
---------------
Here are the specs of the computing nodes:

.. list-table::
   :header-rows: 1

   * - Node type
     - Description
     - Nodes count
     - CPU
     - Cores
     - Frequency
     - RAM
     - GPU
   * - Login
     - Entry point to the cluster
     - 1
     - Xeon Silver 4410Y
     - 24
     - 2.0 GHz
     - 128 Gb
     - --
   * - CPU
     - General-purpose CPU nodes
     - 4
     - Xeon Gold 6354
     - 36
     - 3.0 GHz
     - 256 Gb
     - --
   * - GPU
     - Nodes equipped with NVIDIA graphic cards
     - 1
     - Xeon Gold 6354
     - 36
     - 3.0 GHz
     - 256 Gb
     - 2 x Nvidia A30 24 Gb
   * - FAT
     - Nodes for memory-intensive jobs
     - 1
     - Xeon Gold 6354
     - 36
     - 3.0 GHz
     - 1024 Gb
     - --

The total amount of cores on the 6 computing nodes is 216 cores, the total amount of RAM is 2.3TB.

Each GPU node has 2 physical Nvidia A30 GPUs, one of which is split into 4 virtual 6Gb sub-GPUs (MIG devices). See the `User guide <user_guide.html>`_ for further information on their usage.
 
Hyperthreading is disabled on all the nodes.

Storage nodes
-------------

.. list-table::
   :header-rows: 1

   * - Level
     - Description
     - Storage
     - Total space
   * - 1st (fast)
     - Fast I/O operations
     - 10 x 3.84 Tb SAS in RAID5
     - 30 Tb
   * - 2nd (slow)
     - Data storage for home and shared folders
     - 6 x 18 Tb SAS III in RAID6
     - 70 Tb

All storage nodes are equipped with a Xeon Gold 5317 processor at 2.0GHz with 24 cores and 256 Gb or RAM.

Network
-------

The **network** is based on Gigabit Ethernet for management purposes, and on InfiniBand 200Gbit, a low latency and high bandwidth network.