High Performance Computing at TU Delft

If you’re a researcher or student at TU Delft and you need more computational power than your laptop can offer — whether for running simulations, training machine learning models, or processing large datasets — DelftBlue and DAIC are your go-to resources.

While the documentation of the clusters can be sufficient for frequent users, for preliminary users it can be less clear especially if not used before. I tend to forget some stuff myself and always in learning mode. With the intention of best way for learning something is to teach it! This post walks you through everything you need to get connected and start working on TU Delft’s High Performance Computing (HPC) clusters.

This tutorial is aimed at the TU Delft community but can be useful as well with similar HPC systems.

Full documentation DelftBlue: doc.dhpc.tudelft.nl/delftblue Full documentation DAIC: https://daic.tudelft.nl/

What is DelftBlue & DAIC?

DelftBlue is TU Delft’s supercomputer, maintained by the Delft High Performance Computing Centre (DHPC). It gives you access to hundreds of compute nodes, GPUs, and large amounts of memory — resources that would be impossible to run on a personal machine especially multiple jobs in parallel.

Both cluster uses the SLURM job scheduler, meaning you submit jobs to a queue and the system allocates resources for you automatically. This allocation usage and priority is based on your account access.

Step 1: Check Your Access

Do you already have access?

DelftBlue share is divided into Education 13% | Innovation 5% | Research 82%

• TU Delft employees (PhD candidates, postdocs, staff): you should be able to connect using your NetID for the innovation share. However, for the research share you have to request access from here DelftBlue Research Access. For the DAIC, you have to be affiliated with a contributing group see here DAIC Research Access
• BSc/MSc students: you need to request an account via this form.
• Guest researchers (non-TU Delft): follow the guest access procedure.

Your NetID is your TU Delft username (e.g., ****@tudelft.nl). You’ll use it for everything.

Step 2: Connect to the TU Delft Network (EduVPN)

Important: You cannot SSH directly into DelftBlue from outside the university network. You must first connect via VPN.

If you are on campus (connected to TU Delft Wi-Fi or ethernet), you can skip this step.

If you are off campus, install and connect to EduVPN with “Institute Access”:

1. Download EduVPN from tudelft.nl/en/library/…/access-via-vpn.
2. Open EduVPN and select TU Delft as your institution.
3. Choose “Institute Access” (not “Secure Internet”).
4. Log in with your NetID credentials.

Once connected, your machine is effectively on the TU Delft network and you can proceed.

Step 3: SSH into DelftBlue

SSH (Secure Shell) is the standard way to connect to remote servers. The DelftBlue login address is:

login.delftblue.tudelft.nl

This will route you to one of four login nodes: login01, login02, login03, or login04.

On Windows

Option A — Command Prompt (Windows 10 or higher)

Windows 10+ includes SSH natively. Open Command Prompt or PowerShell and run:

ssh <netid>@login.delftblue.tudelft.nl

Replace <netid> with your actual TU Delft username. Enter your password when prompted.

Option B — All-in-one GUI clients

If you prefer a graphical interface, two popular options are:

• Bitvise SSH Client — combines a terminal and an SFTP file manager in one window.
• MobaXterm — another widely-used all-in-one SSH client with X11 forwarding support.

Both are free and require no command-line setup.

On Linux / macOS

Open your terminal and run:

ssh <netid>@login.delftblue.tudelft.nl

To enable GUI applications over SSH (X11 forwarding), add the -X flag:

ssh -X <netid>@login.delftblue.tudelft.nl

For file browsing via SFTP in your Linux file manager, type the following in the address bar:

sftp://<netid>@login.delftblue.tudelft.nl

On Android

Use ConnectBot, a free SSH client app. Configure it with:

• Host: login.delftblue.tudelft.nl
• Username: your NetID

Step 4: Explore Your Home Directory

Once logged in, you’ll be greeted by a shell prompt on one of the login nodes:

[<netid>@login01 ~]$

Your home directory lives at /home/<netid>/. You also have a scratch directory at /scratch/<netid>/, which is a symlink from your home folder:

[<netid>@login01 ~]$ ls -la
...
lrwxrwxrwx  1 <netid> domain users  21 Mar 17 14:27 scratch -> /scratch/NetID
drwx------  2 <netid> domain users   4 Mar 17 11:10 .ssh
...

Note: The scratch space is for temporary computation files and is not backed up. Store important outputs in your home directory or project storage.

Step 5: (Optional) Set Up SSH Keys for Passwordless Login

Typing your password every time gets old. SSH keys let you log in without a password and are more secure.

Generate an SSH key pair on your local machine:

ssh-keygen -t ed25519 -C "your_email@tudelft.nl"

Accept the default file location (~/.ssh/id_ed25519) and optionally set a passphrase.

Copy your public key to DelftBlue:

ssh-copy-id <netid>@login.delftblue.tudelft.nl

Or manually append the contents of ~/.ssh/id_ed25519.pub to ~/.ssh/authorized_keys on DelftBlue.

From now on, ssh <netid>@login.delftblue.tudelft.nl will log you in without a password prompt.

Step 6: (Optional) Create an SSH Config File

If you connect frequently, an SSH config file saves you from typing the full address every time.

Edit (or create) ~/.ssh/config on your local machine:

Host delftblue
    HostName login.delftblue.tudelft.nl
    User <netid>
    IdentityFile ~/.ssh/id_ed25519

Now you can connect simply by typing:

ssh delftblue

Step 7: Alternative — Open OnDemand (Web Browser Access)

Not comfortable with the command line? DelftBlue also offers Open OnDemand, a web-based portal with a full graphical interface.

Visit: https://login.delftblue.tudelft.nl/

Through Open OnDemand you can:

• Manage files — upload and download via your browser
• Open a shell — a terminal directly in your browser tab
• Launch interactive apps — Jupyter Lab, MATLAB, RStudio, VS Code, ParaView, remote desktops
• Monitor Slurm jobs — check the status of your queued and running jobs

This is a great starting point if you are new to HPC or want a more familiar environment.

What’s Next?

Once you’re connected, you’ll want to learn how to:

Quick Reference

# Connect (on TU Delft network or EduVPN)
ssh <netid>@login.delftblue.tudelft.nl

# Connect with X11 forwarding (Linux/macOS)
ssh -X <netid>@login.delftblue.tudelft.nl

# SFTP file transfer
sftp <netid>@login.delftblue.tudelft.nl

# Copy a file to DelftBlue
scp myfile.txt <netid>@login.delftblue.tudelft.nl:~/

# Copy a file from DelftBlue
scp <netid>@login.delftblue.tudelft.nl:~/results.txt ./

Happy computing! If you run into issues, check the DelftBlue FAQ or reach out to DHPC support.