Can I use a faster CPU for GitHub Actions?

How do I run GitHub Actions on a faster CPU?

Yes, you can: GitHub Actions runs a job on whatever machine its runs-on label points to, so pointing that label at a runner on a faster CPU is a one-line change. GitHub’s own hosted runners let you pick a core count, not a CPU model. Sengi runs every job on an AMD Ryzen 9 7950X3D desktop CPU boosting past 5 GHz, the same model on every job, with up to 3× the multi-core and 1.65× the single-core throughput of GitHub’s 2 vCPU runner, at $0.003 a minute against GitHub’s $0.006.

Last checked October 23, 2026, against GitHub’s hosted-runner reference. CPU and build figures measured on Sengi in October 2026 against GitHub’s runner of the same size.

Which jobs does a faster CPU speed up?

Anything that spends its time computing rather than waiting. Measured on Sengi against GitHub’s runner of the same size:

The 4 vCPU rows are RunsOn’s open benchmark harness, run on Sengi October 9, 2026, against RunsOn’s published GitHub results; the 2 vCPU rows are medians measured in October 2026 against ubuntu-latest.

Why does the same CPU on every job matter?

On a hosted runner whose CPU varies, the same commit can take noticeably different times on two runs, which hides real regressions and makes timeouts hard to set. Sengi runs every job on the same AMD Ryzen 9 7950X3D, on bare metal with local NVMe, so a slower build means slower code. More in faster GitHub Actions runners and GitHub Actions runner specs.

How do I switch a job to the faster CPU?

jobs:
  build:
-   runs-on: ubuntu-latest
+   runs-on: sengi-standard-2-ubuntu-2404   # or sengi-standard-4-ubuntu-2404, sengi-standard-8-ubuntu-2404

Merge, and the next run lands on the 5 GHz CPU. See how switching works and the runner comparison.

Frequently asked questions

What CPU does GitHub Actions use?

GitHub does not publish a CPU model for its Linux and Windows hosted runners. They are virtual machines on cloud server CPUs, and the model varies by job: the jobs we measured landed on four different server CPUs.

Does single-core speed matter for CI?

Yes, more than most teams expect. Test runners, linkers, bundlers, type checkers and much of a Docker build run on one or a few threads, so a faster core shortens them where more cores cannot. On Sengi's 5 GHz cores, a TypeScript typecheck ran 1.5× faster than on GitHub's runner of the same size.

Can I choose the CPU on a GitHub larger runner?

No. A GitHub larger runner is sized by cores, memory and disk; GitHub does not offer a choice of CPU model. Choosing the CPU means choosing a runner provider that publishes it.

Does a faster CPU cost more on Sengi?

No. Sengi's AMD Ryzen 9 7950X3D runners cost $0.003 a minute at 2 vCPU, $0.006 at 4 and $0.012 at 8, half GitHub's $0.006 and $0.012 at 2 and 4 vCPU and 45% under its $0.022 at 8 vCPU.