Skip to content



  • We'll get an overview of UPPMAX and SNIC/NAISS and how a computer cluster works

UPPMAX = UppMACS - Uppsala Multidisciplinary Center for Advanced Computational Science


UPPMAX missions

  • Runs the clusters placed in Uppsala.
  • More details in the afternoon about Organisational orienteering!

UPPMAX systems

  • Clusters
    • Rackham (general purpose)
      • Snowy (Long runs and GPU:s)
    • Bianca (sensitive data)
      • Miarka (new for LifeScience)
  • Storage
    • On-load directly connected to the clusters
    • Off-load for large data not needed for computation analysis anymore
  • Cloud
    • Dis (region EAST-1)

High Performance Computing — HPC

What is a cluster?

  • A network of computers, each computer working as a node.

  • From small scale RaspberryPi cluster...


  • To supercomputers like Rackham.


  • Each node contains several processor cores and RAM and a local disk called scratch.


  • The user logs in to login nodes via Internet through ssh or ThinLinc.

  • Here the file management and lighter data analysis can be performed.



  • The calculation nodes have to be used for intense computing.

Summary about the three "common" UPPMAX clusters

Rackham Snowy Bianca
Purpose General-purpose General-purpose Sensitive
# Nodes (Intel) 486+144 228+
50 Nvidia T4 GPUs
288 +
10 nodes á 2
Cores per node 20/16 16 16/64
Memory per node 128 GB 128 GB 128 GB
Fat nodes 256 GB & 1 TB 256, 512 GB & 4 TB 256 & 512 GB
Local disk (scratch) 2/3 TB 4 TB 4 TB
Login nodes Yes No (reached from Rackham) Yes (2 cores and 15 GB)
"Home" storage Domus Domus Castor
"Project" Storage Crex, Lutra Crex, Lutra Castor

Overview of the UPPMAX systems

  graph TB

  Node1 -- interactive --> SubGraph2Flow
  Node1 -- sbatch --> SubGraph2Flow
  subgraph "Snowy"
  SubGraph2Flow(calculation nodes) 

        thinlinc -- usr-sensXXX + 2FA + VPN ----> SubGraph1Flow
        terminal -- usr --> Node1
        terminal -- usr-sensXXX + 2FA + VPN ----> SubGraph1Flow
        Node1 -- usr-sensXXX + 2FA + no VPN ----> SubGraph1Flow

        subgraph "Bianca"
        SubGraph1Flow(Bianca login) -- usr+passwd --> private(private cluster)
        private -- interactive --> calcB(calculation nodes)
        private -- sbatch --> calcB

        subgraph "Rackham"
        Node1[Login] -- interactive --> Node2[calculation nodes]
        Node1 -- sbatch --> Node2

Next session

We will try the different forms to log in to Bianca!


  • NAISS makes available large-scale high-performance computing resources, storage capacity, and advanced user support, for Swedish research.
  • UPPMAX runs the local resources placed at Uppsala University
  • A cluster consists of several inter-connected computers that can work individually or together.