Since we released GitHub Codespaces in 2021, we’ve made a number of updates aimed at improving usability, controlling cost, and more (for example, free usage for all, one click into templates, and concurrency policies). Now, GitHub has improved our developer experience and reduced usage costs at the same time by taking advantage of new virtual machines that provide all of our users twice the RAM, and approximately 10-30% improved CPU performance after adopting Advanced Micro Devices (AMD)-based hosts. These changes enable you to achieve the same (or better) machine performance for half the cost of the previous machine generation.

How this change helps you

In our previous VM generation, memory intensive workloads often had to overprovision CPUs just to get enough RAM in order to run, particularly when running multiple services. For professional developers this was particularly frustrating because of the increased complexity of their development environments, and their higher expectations for performance. Now, rather than having to choose between paying a premium for larger developer machines or sacrificing developer experience and productivity, you can get the best of both worlds.

For example, at GitHub we use our own software and services to build GitHub itself. GitHub uses Codespaces to build not only Codespaces, but the entire platform. GitHub has a large Ruby monolith that requires significant CPU and RAM to test, and also sets an extremely high bar for developer experience. In order to operate these environments while maximizing developer happiness, GitHub used the largest virtual machines available in Codespaces.

Once the new machine types were available, GitHub’s internal developer experience (DX) team started by moving a few dev teams with RAM-hungry workflows to machines with half the CPU count, but the same RAM, to test whether they would be sufficient. With very little effort, and nearly zero developer impact, testing showed that developers were just as successful on the smaller machines, and GitHub incurred half the cost. As additional teams tried moving the fewer-core machines, there was only one build process that turned out to be CPU architecture dependent. The fix was simple—to specify the CPU architecture so that QEMU could emulate appropriately. No other negative impacts were identified.

Due to the success of the initial trials, we quickly rolled out the changes to more teams. The result? Approximately 50% savings!

Figure 1: Codespaces cost for GitHub during the introduction of the AMD machines

Since we’ve rolled out the AMD machines for GitHub, we’ve seen no problems and had only happy users.

You can do the same in your organization by working with your development teams using GitHub Codespaces to test smaller machines on your existing development environments. All Codespaces virtual machines have been upgraded, so testing is as simple as having some developers try working in a smaller machine than they usually do. In most cases, no other configuration changes are necessary!

Once you have found the sweet spot for performance and experience, you can set a policy within your organization to restrict machine types, ensuring cost controls while providing environments that allow your developers to do their best work.

Save costs while empowering your developers

Now that these changes are in your hands, we invite you to see how much more you can get out of GitHub Codespaces by taking advantage of the improved processing power and increased headroom the RAM provides. As ever, please reach out to your account team, or participate in the GitHub Codespaces Community Discussions to provide us your feedback.