GitHub recently announced the public preview of Linux arm64 hosted runners for GitHub Actions. Free for public repositories, this update provides developers with more efficient tools for building and testing software on Arm-based architectures.
A changelog post on GitHub Blog summarised the announcement. Arm64 runners are hosted environments that enable developers to execute workflows, eliminating the need for cross-compilation or emulation. These 4 vCPU runners, using Cobalt 100 processors, can provide up to a 40% CPU performance increase compared to the previous generation of Microsoft Azure’s Arm-based virtual machines.
The addition of arm64 runners aligns with the increasing demand for arm-based computing, driven by the energy efficiency and performance advantages of the architecture.
Native arm64 execution provides benefits such as faster build times and more reliable testing outcomes compared to emulated environments. At the time of arm64 release on GitHub Actions in June 2024, GitHub had supported Ubuntu and Windows VM images for these runners, enabling a straightforward start for users building on Arm. However, back in June, these runners were available to GitHub Team and Enterprise Cloud Plans customers only.
To use the arm64 hosted runners, include these labels in your workflow files within public repositories: ubuntu-24.04-arm and ubuntu-22.04-arm. These labels are only functional in public repositories; workflows in private repositories using these labels will fail.
Standard runners usage limits, including maximum concurrency based on your plan, apply to all runs in public repositories. Developers are advised to expect potentially longer queue times during peak hours while the arm64 runners are in public preview.
The tech community on Hacker News welcomed this development as we saw interesting discussion threads. One user highlighted how this feature could encourage a broader shift toward ARM-based cloud workflows, mentioning the cost-effectiveness of arm CPUs compared to x64.
Another thread enquired about pricing differences between arm64 and x64 instances. One HN user agartner also provided an example of how to use the native GitHub Actions arm runners to accelerate docker builds.
This capability is particularly beneficial for projects targeting arm devices, such as IoT applications, mobile platforms, and cloud-native services. GitHub has encouraged users to share their experiences and suggestions by joining the community discussion.
For further details, interested readers can visit the documentation and also view a list of VM images from GitHub partners.
