In early 2025 Hetzner added Ampere ARM instances to its Cloud. Aggressive pricing, promised performance. We ran them for two months on three real workloads.
The instances
CAX VPS start at CAX11 (2 vCPU Ampere, 4 GB RAM, 80 GB SSD) at €4.49/mo. CAX21 (4 vCPU, 8 GB) at €7.49/mo. 25-35% cheaper than equivalent x86 (CPX).
Test 1: Node.js + Express API
Throughput on CAX21: ~14,500 req/s on a simple JSON endpoint. On CPX21 (x86 AMD): ~13,800 req/s. ARM wins narrowly. p99 latency: 8 ms vs 9 ms.
Test 2: Postgres 16
pgbench (TPC-B-like): 2,890 TPS on CAX21 vs 2,620 TPS on CPX21. ARM +10%.
Test 3: Next.js build
Building a medium app of ours (3,200 TS files, 800 deps) takes 89s on CAX21 vs 78s on CPX21. x86 wins. Bottleneck is webpack, with native optimisations still x86-leaning.
Compatibility
- Node.js: excellent. Everything compiles.
- Sharp: install the ARM version (npm resolves automatically).
- Prisma: excellent ARM support since 5.x.
- Docker images: often multi-arch; a few third-party images are x86-only — verify first.
When to pick
| Case | Pick |
|---|---|
| Node.js / Postgres APIs | ARM (-30% cost, +10% perf) |
| CI builds / webpack-heavy | x86 |
| Generic containers | ARM, except specific images |
| Self-hosted analytics, BI | ARM |
For most of our runtime workloads, ARM is the new default. For CI or builds we stick to x86 until tooling catches up.