Blacksmith runner benchmarks and hardware details
The Blacksmith sample includes two-vCPU Linux x64, Linux ARM64, and Windows runners, plus a six-vCPU macOS runner. Each CPU test uses one execution thread. Linux and Windows pin it to one logical CPU, while the macOS thread can migrate. The operating system and compiler are part of the result, so the four configurations aren't interchangeable measurements of a processor alone.
By TechCompare · Updated
Separate the native cache from GitHub cache
Where both backends verified all three save and restore pairs, the tool lets you inspect them separately. Transfers use a 512 MiB random payload and restore on a fresh runner job. This measures the archive service and action overhead under a controlled transfer, rather than a complete dependency installation. A real package cache can compress differently and may include many small files.
Read the runner size as a request
Blacksmith documents Linux and Windows sizes up to 32 vCPUs and macOS sizes up to 12. Its documentation also describes free capacity upgrades, so a workflow label is a requested tier rather than proof of the exact allocation during a test. The reports don't preserve that allocation. Prices are attached to the requested tier, with that limit visible in the hardware details.
Calculator
| RunnerRunner | CPUCPU scoreSingle thread | CPU valueCPU value | DiskDisk score | CacheCache score | InternetInternet score | Cost/vCPU/minCost/vCPU/minUSD | Max vCPUMax runner vCPU |
|---|---|---|---|---|---|---|---|
| Blacksmith Linux x64 AMD EPYC (model hidden) | 45,851 | 22.9M/USD | 1,331.6 | 154.4 | 741.9 | 0.002 | 32 |
| Blacksmith macOS arm64 Apple M4 Pro | 41,001 | 3.1M/USD | 262.4 | 262.9 | 244.5 | 0.0133 | 12 |
| Blacksmith Windows x64 AMD EPYC 4565P 16-Core | 40,527 | 10.1M/USD | 708.9 | 24.8 | 731.2 | 0.004 | 32 |
| Blacksmith Linux arm64 ARM64 (model undisclosed) | 27,191 | 21.8M/USD | 320.8 | 88.2 | 616.7 | 0.0013 | 32 |
Single thread CPU: CoreMark iterations/s. Disk and cache: composite MiB/s. Internet: composite Mbps. Value: score ÷ USD cost/vCPU/min. K means thousand, M means million. Higher is better. Cache uses each runner's best tested cache or artifact backend. Limits: maximum runner vCPU. Prices and value use USD. RunJob's EUR rate is converted at €1 = $1.1206 (ECB, 2026-10-09).
Open the full GitHub Actions runner benchmark toolMeasurement context
The Linux x64 guest reports AMD EPYC without a model number. Windows identifies EPYC 4565P, and macOS identifies M4 Pro. The Linux ARM guest reports only aarch64. The table preserves those differences instead of assigning the same specific processor to every Blacksmith runner.
Verdict
Read the CPU and cache results together if dependency reuse is a large part of your CI runtime. Keep a hidden CPU SKU marked as hidden. A similar score doesn't prove that two guests share the same host processor.
More runner benchmark scenarios
Frequently asked questions
Are these independent GitHub Actions runner benchmarks?
Does a CoreMark score predict my build time?
How are disk, cache, and internet scores calculated?
How is price per minute per vCPU calculated?
What does CPU value mean?
Why is an exact CPU model sometimes missing?
Are missing tests counted as zero?
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