Edoardo Barbieri
on 30 July 2025
If you’re here, you likely already know about preemption, determinism, and real-time capable operating systems. If that’s the case, and you want to learn how to get up and running with Real-time Ubuntu, skip ahead now to find out how to enable the kernel on your workstation.
If you’d like a short refresher, we have a three-part blog series on real-time Linux for beginners. On the other hand, if you’re more interested in the business impact a real-time OS can have across industries, this whitepaper explains the benefits of real-time compute for enterprises, explores industry use-cases, and will show you how to unlock the potential of real-time compute in your business. And, finally, if you’re more technically savvy, this CTO’s guide to real-time Linux is probably what you’re looking for.
Real-time Ubuntu is Ubuntu with a real-time kernel, which includes the PREEMPT_RT patchset. It changes Linux’s default scheduler to a priority-based one, increasing predictability by modifying the existing kernel code. As a consequence, Real-time Ubuntu is more pre-emptive than mainline, delivering determinism and lower latency.
Available Versions and Long-Term Support
Real-time Ubuntu is available across both LTS and interim Ubuntu releases, offering flexibility to individual developers and enterprises alike to experiment with the latest software and features, while having the peace of mind of support.
Open access to Real-time Ubuntu
The deb packages of various Real-time Ubuntu releases, from 22.04 LTS to the interim 25.04, have been openly released and are now available for free for anyone to access. Anyone can install them via the Ubuntu Universe repository, an archive which makes it easy to install new software tested and built specifically for each version of Ubuntu.
Version | Code name | Real-time Kernel Version | Access |
Ubuntu 25.04 | Plucky Puffin | 6.14 | Source package |
Ubuntu 24.10 | Oracular Oriole | 6.11 | Source package |
Ubuntu 24.04 LTS | Noble Numbat | 6.8 | Source package |
Ubuntu 22.04 LTS | Jammy Jellyfish | 5.15 | Source package |
For open access to the real-time kernels above available in Universe:
sudo add-apt-repository universe
sudo apt update
sudo apt install ubuntu-realtime
Note that the Universe repository contains community-maintained free and open-source software, and only a teaser of the real-time kernel is available in Universe for LTS releases. To receive updates for the LTS samples, an Ubuntu Pro subscription is necessary.
While the real-time kernel packages are openly available and provide a great way to test real-time capabilities ahead of the next LTS, developers and enterprises deploying to production can receive security patching for all the software in the repository for 10+ years with Ubuntu Pro.
Ubuntu Pro is a subscription for open-source software security by Canonical, providing security and compliance on top of Ubuntu LTS, with 10+ years of coverage for over 25,000 packages.
Ubuntu Pro is always free for personal use, and anyone can use it for free on up to 5 machines, or 50 if you are an official Ubuntu Community member. Furthermore, enterprises receive a 30-day trial.
LTS Releases of Real-time Ubuntu Server with Ubuntu Pro
Canonical provides up to 12 years of security maintenance and a continuous stream of critical updates to the real-time kernel variants for Ubuntu LTS versions under the Ubuntu Pro subscription. The generic release of Real-time Ubuntu is available on AMD64 and ARM64, whereas silicon-optimised variants are available on Intel hardware (22.04 LTS with support for Intel Time Coordinated Computing and IEEE 802.1 Time Sensitive Networking ), and Raspberry Pi.
Version | Code name | Real-time Kernel Version | Variants |
Ubuntu 22.04 LTS | Jammy Jellyfish | 5.15 | generic, Intel-optimised |
Ubuntu 24.04 LTS | Noble Numbat | 6.8 | generic, Raspberry-Pi optimised |
If you’re using an LTS release of Ubuntu and have Ubuntu Pro enabled, enabling the real-time kernel is straightforward. First, if you have not yet attached your machine to an Ubuntu Pro subscription, you will need to do so in order to enable Real-time Ubuntu. You can do so by running the following command:
sudo pro attach
Otherwise, select the correct version for your OS and processor, and use the corresponding commands below to enable the appropriate kernel variant:
Generic on Ubuntu 22.04 LTS or Ubuntu 24.04 LTS:
sudo pro enable realtime-kernel
Raspberry Pi 4 or 5 on Ubuntu 24.04 LTS:
sudo pro enable realtime-kernel --variant=raspi
Optimized Real-time Ubuntu is production-ready on Intel Atom® X6000E Series Processors, as well as 11th, 12th and 13th Gen Intel® Core™ processors:
Intel Atom and Intel Core processors on Ubuntu 22.04 LTS:
sudo pro enable realtime-kernel --variant=intel-iotg
Reboot your system, and you’re ready to run Real-time Ubuntu.
LTS Releases of Real-time Ubuntu Core
The real-time kernel is also available for Ubuntu Core, Canonical’s embedded version of the Ubuntu OS. Ubuntu Core is Ubuntu for IoT and embedded devices, with a strong focus on robust security, a streamlined update mechanism, and a simplified developer experience. While Ubuntu Core is similar to standard Ubuntu – open source, binary-compatible and backed by a strong developer community – it is specifically designed for the world of embedded and cybersecurity compliance.
Ubuntu Core Version | Real-time kernel version |
Core 22 | 5.15 |
Core 24 | 6.8 |
In order to run Ubuntu Core with the real-time kernel, we first need to create and build a Real-time Ubuntu Core image.
Let’s get you to production
Canonical delivers Real-time Ubuntu with the same commitment to security, stability, and open-source leadership as the rest of the Ubuntu ecosystem. With deterministic performance, long-term support, and easy access across edge and cloud environments, Real-time Ubuntu enables enterprises to focus on their value proposition.
We partner with silicon vendors, board manufacturers and ODMs to shorten enterprises’ time-to-market. Reach out to our team for custom board enablement, commercial distribution, long-term support or security maintenance.
Further Reading
A CTO’s guide to real-time Linux
Is a real-time OS right for your business?
Cyber Resilience Act: Yocto or Ubuntu Core for embedded devices?