RunsOn m8azn.xlarge · gp3 1000 MiB/s vs Blacksmith 4 vCPU x64
RunsOn does each build for 1.1–1.3× less; on time, Blacksmith is faster on the Docker build and tied on the Rust and TypeScript builds. Both 4 vCPU x64.
All three builds 1.1× cheaper on RunsOn: $0.0645 vs $0.0728Blacksmith 1.1× faster: 8m 12s vs 9m 21s
Rust build 1.3× cheaper on RunsOn: $0.0136 vs $0.0175about the same time: 1m 54s · 1m 59s
TypeScript build 1.2× cheaper on RunsOn: $0.0072 vs $0.0089about the same time: 45s · 54s
Docker build 1.1× cheaper on RunsOn: $0.0437 vs $0.0464Blacksmith 1.3× faster: 5m 19s vs 6m 42s
RunsOn m8azn.xlarge · gp3 1000 MiB/s
jobs ran from Amazon.com (US)
Blacksmith 4 vCPU
jobs ran from Secured Servers (US)
Side by side
Every measurement both runners share, cost first. The dot marks the better value; gap is the larger over the smaller.
| Measurement | RunsOn | Blacksmith | Gap |
|---|---|---|---|
| Cost | |||
| Cost per Rust build | $0.0136 | $0.0175 | 1.3× RunsOn |
| Cost per TypeScript build | $0.0072 | $0.0089 | 1.2× RunsOn |
| Cost per Docker build | $0.0437 | $0.0464 | 1.1× RunsOn |
| Price per minute | $0.0047 | $0.0080 | 1.7× RunsOn |
| Real builds, wall time | |||
| Rust build (spotify-player) | 1m 54s | 1m 59s | ≈ even |
| TypeScript build (opencode) | 45s | 54s | ≈ even |
| Docker build (PostHog) | 6m 42s | 5m 19s | 1.3× Blacksmith |
| CPU & memory | |||
| PassMark single-thread (points) | 4,257 | 4,236 | ≈ even |
| PassMark CPU Mark, all cores (points) | 15,102 | 15,036 | ≈ even |
| sysbench CPU, 1 thread (events/s) | 6,220 | 6,419 | ≈ even |
| 7-Zip compression (MIPS) | 31,030 | 27,863 | 1.1× RunsOn |
| Memory read bandwidth | 40.8 GiB/s | 31.5 GiB/s | 1.3× RunsOn |
| Measurement | RunsOn | Blacksmith | Gap |
|---|---|---|---|
| Workspace disk (fio) | |||
| Random read, 4k QD32 (IOPS) | 15,994 | 873,112 | 54.6× Blacksmith |
| Random write, 4k QD32 (IOPS) | 15,991 | 251,762 | 15.7× Blacksmith |
| Random read, 4k QD1 (IOPS) | 1,775 | 84,854 | 47.8× Blacksmith |
| QD1 read latency, p99 | 856 µs | 14 µs | 59.9× Blacksmith |
| Sequential read | 1,002 MiB/s | 6.9 GiB/s | 7.1× Blacksmith |
| Sequential write | 1,001 MiB/s | 1.6 GiB/s | 1.7× Blacksmith |
| Sync write, 4k + fdatasync (IOPS) | 540 | 18,024 | 33.4× Blacksmith |
| Network, cache & Docker | |||
| Download from GitHub | 256 MiB/s | 107 MiB/s | 2.4× RunsOn |
| Cache restore, 4 GB (actions/cache) | 10s | 14s | 1.4× RunsOn |
| Cache save, 4 GB (actions/cache) | 14s | 8s | 1.8× Blacksmith |
| docker pull | 5.0s | 6.5s | 1.3× RunsOn |
| Database | |||
| pgbench read/write (TPS) | 3,758 | 11,775 | 3.1× Blacksmith |
| pgbench read-only (TPS) | 163,575 | 89,914 | 1.8× RunsOn |
| Queue | |||
| Queue under burst load | 20s | 11s | 1.8× Blacksmith |
- ≈ even: under 5% apart, or a build inside both runners' run-to-run spread
- Queue: identical jobs queued at the same instant (burst suite)
- RunsOn at EC2 spot, its default (7-day average of the cheapest us-east-1 zone's spot price, fetched 5 Oct 2026); the jobs ran on spot
- Cost: a managed SaaS runner against RunsOn self-hosted on your AWS account; the effort of running it was not measured