The Blacksmith cache co-locates cache artifacts in the same datacenter park as the bare metal instances running our VMs, and can almost saturate the NIC on our runners. GitHub’s cache action stores cache artifacts in Azure Blob Storage, which generally performs poorly when the action runner is not co-located in the same AZ as the storage.

The Speed Difference

The standard GitHub cache, usually gets you up to 100MB/s. With the Blacksmith cache we have seen customer workflows download at speeds of over 400MB/s.

Cache Size

The Blacksmith cache provides 25GB of free storage per repo per week, a substantial increase from GitHub’s 10GB to maximize your cache hits. Like GitHub, our cache also evicts the least recently used cache entries that were last accessed more than 7 days ago.

The Blacksmith cache is a drop-in replacement for GitHub’s cache action, actions/cache. To migrate, refer to our guide.