# Benchmarks (/performance/benchmarks)



StarSling runners can deliver up to 6x faster build times compared to GitHub-hosted runners, depending on workload characteristics. The best way to see the difference is to benchmark your own workflows — the guide below shows how.

## Real-World Results

What StarSling delivered for real teams after they switched `runs-on` — faster runners plus the optimizations StarSling agents shipped and the team merged:

| Repo                                                       | Metric               | GitHub-hosted | StarSling | Improvement      |
| ---------------------------------------------------------- | -------------------- | ------------- | --------- | ---------------- |
| [Mastra](https://starsling.dev/customers/mastra)           | Slowest test suite   | \~30m         | \~5m      | **\~6x faster**  |
| [Mastra](https://starsling.dev/customers/mastra)           | Job queue under load | \~15m         | under 2m  | **\~8x shorter** |
| [Better Auth](https://starsling.dev/customers/better-auth) | E2E runtime per job  | 2m 22s        | 1m 04s    | **\~2x faster**  |

Across all its CI and E2E jobs, Better Auth saves roughly **20,000 CI minutes every month**.

<Callout type="info">
  These are live customer results — each links to its case study with the full methodology and the agent-authored PRs behind the numbers.
</Callout>

## Why StarSling is Faster

### 1. 30% Faster Hardware

| Spec   | GitHub-hosted                 | StarSling        |
| ------ | ----------------------------- | ---------------- |
| CPU    | 4th Gen AMD EPYC<sup>\*</sup> | 5th Gen AMD EPYC |
| Cores  | 4 vCPU                        | 4 vCPU           |
| Memory | 16 GB                         | 16 GB            |

5th Gen AMD EPYC processors deliver \~30% better single-threaded performance over 4th Gen, directly improving build and test execution times.

<small>
  ** Not publicly disclosed by GitHub in [their docs](https://docs.github.com/en/actions/using-github-hosted-runners/using-github-hosted-runners/about-github-hosted-runners) but inferred based on publicly available information.*
</small>

### 2. Unlimited Concurrency

No concurrency limits means every job gets a runner quicker, even during peak CI loads.

## Run Your Own Benchmark

Compare your actual workflows side by side — run the same steps on a GitHub-hosted runner and a StarSling runner, then compare the timings:

```yaml title=".github/workflows/benchmark.yml"
jobs:
  github-hosted:
    runs-on: ubuntu-latest
    steps:
      - uses: actions/checkout@v4
      - run: time npm ci && time npm run build

  starsling:
    runs-on: starsling-ubuntu-24.04
    steps:
      - uses: actions/checkout@v4
      - run: time npm ci && time npm run build
```

<Cards>
  <Card title="Compute Sizing" href="/runners/compute-sizing" description="Choose the right runner size" />

  <Card title="Customer Results" href="https://starsling.dev/customers" description="Before/after numbers from real repos" />
</Cards>