Short answer
Each provider's own page describes caching differently: GitHub-hosted gives 10 GB per repository; Blacksmith and Depot publish speed claims for their caches (4x faster downloads, up to 1000 MiB/s and 10x faster) which CI Bench did not verify; WarpBuild prices cache storage ($0.20 per GB-month) and operations; RunsOn stores cache in S3 in your own VPC. CI Bench v1 measured whole-job times with each provider's documented accelerators used, not cache throughput. Maintained by Vitko, Inc., which sells one of the products measured.
What each page says
| Provider | What its page says | Source |
|---|---|---|
| GitHub-hosted | Cache storage 10 GB per repository on every plan; more is billed. | GitHub Docs, billing for GitHub Actions, read 2026-10-27 |
| Blacksmith | Says "4x faster cache downloads" on its pricing page; Docker layer caching and sticky disks are add-ons at +$0.50 per GB a month. | Blacksmith pricing, read 2026-10-27 |
| Depot | Says runners are integrated into its cache system, with upload and download speeds up to 1000 MiB/s and "10x faster caching"; cache is scoped by repository. | Depot docs, overview, read 2026-10-27 |
| WarpBuild | Cache storage $0.20 per GB-month and $0.0001 per cache write or restore operation; Docker layer cache offered. | WarpBuild pricing, read 2026-10-27 |
| RunsOn | Cache steps restore from S3 in your VPC with "no size cap"; 10 GB free per repository, more billed (AWS cost); an ephemeral ECR registry for BuildKit layers. | RunsOn, read 2026-10-27 |
| Namespace | Plans list cross-invocation caching and shared Docker builds; check its pricing page for limits. | Namespace pricing, read 2026-10-27 |
| Vitko Runners | No separate cache product; warm starts restore a prepared copy of your setup (private beta); Docker layer caching as a feature is not offered. | Vitko Runners limits, read 2026-10-27 |
Related: Docker builds, measured. Accelerators each provider documents and that were used are listed on its runner page.
More: all questions answered · 12 options compared · ranked by speed · ranked by cost per job · calculator.
Provider pages may have changed since 2026-10-27; they are the authority. Method: how the runs were made; data: results.json; every raw record: the repository. Maintained by Vitko, Inc., which sells one of the products measured. Page dated October 29, 2026.