• Test bed
  • In service
  • Discipline-specific system for Astronomy and Cosmology
  • Funded by STFC, DiRAC, ExCALIBUR
  • 1 nodes, with 1 NVIDIA H100 NVL accelerator per node
  • Benchmarks (1) ▾
    • Memory bandwidth (BabelStream): 3387 GB/s
      • array_size: 134217728
      • iterations: 100
      • precision: FP64
  • Manufactured by NVIDIA
  • Scheduler: Direct SSH
  • Interconnects:

COSMA GH200

COSMA (The Compute Optimised System for Modelling and Analysis) is a High Performance Computing facility hosted at Durham University, operated by the Institute for Computational Cosmology on behalf of DiRAC.

The H100 NVL (Hopper) node is a GPU testbed within COSMA.

Node RAM CPU Access
gn004 510GB 64 cores (Intel Xeon) Direct SSH

The H100 NVL is a high-memory variant of NVIDIA’s H100. It is optimised for LLM Inference because of its high memory bandwidth, compute density, and energy efficiency.

Documentation

Gaining access

Access requires a COSMA account, obtained via the DiRAC SAFE portal.

  1. Create a SAFE account with an institutional email.
  2. Upload an SSH public key on SAFE. If you do not have one, generate with ssh-keygen -t ed25519.
  3. Request a login account. This requires selecting a project, either:
    • Project do016 for NVIDIA GPU testbed access.
    • A DiRAC project code for a given allocation (provided by a supervisor).
  4. Wait for the account to be approved by the project manager. Keep an eye on your email!
  5. Connect to COSMA via SSH: ssh username@login8.cosma.dur.ac.uk (Note: On first login you will be asked to change the password provided in your email)

Visit https://cosma.readthedocs.io/en/latest/account.html for more details. Contact cosma-support@durham.ac.uk for any questions.

Usage

Connect directly to gn004 via SSH from a login node:

ssh gn004
nvidia-smi
./gpu_program_to_run

Restrictions

  • Shared resource. Before running large jobs, check if others are using the nodes. Access is SSH only, so there is no SLURM queue
  • CUDA is available via module load nvhpc/25.11