Hetzner ARM (Ampere)

What Hetzner ARM actually is

This entry covers one specific slice of Hetzner Cloud: the CAX line, the arm64 servers built on Ampere Altra processors. Hetzner introduced them on 12 April 2023 — the first Arm-based machines in its cloud — as four plans with up to 16 vCPUs, up to 32GB of ECC RAM and up to 320GB of NVMe storage. Everything else about them is standard Hetzner Cloud: the same console, the same REST API and CLI, the same one-click apps, the same hourly billing and the same network. The difference is the instruction set, and that difference is the whole review.

The headline is price per core. Arm64's efficiency advantage means Hetzner can sell shared Ampere cores for less than x86 equivalents: at launch the entry CAX11 cost €3.79/month including an IPv4 address with no setup fee and no minimum contract. Hetzner has since reorganised its catalog into generation-based families — Cost-Optimized, Regular Performance and General Purpose — and the CAX plans now sit in the Cost-Optimized family, which reuses proven hardware generations and warns that available server numbers are limited. At the time of writing the catalog lists the entry CAX11 from €6.49/month including IPv4 (excl. VAT, €0.0104/hour) and the top CAX41 — 16 Ampere vCPUs, 32GB RAM, 320GB NVMe — at €41.49/month (€0.0665/hour). Prices exclude VAT and vary by location.

For the general platform — locations, API quality, our benchmark numbers on the x86 CX line — see our main Hetzner Cloud coverage and the /benchmarks page. Here we stay on the Arm question: what you gain, what you give up, and who should actually buy these.

Pricing: what you really pay

Structure first, because it is the same honest model Hetzner runs everywhere. Servers are billed hourly up to a monthly cap: delete a server mid-month and you pay only the hours it existed. Traffic is generous — EU locations include at least 20TB, with additional traffic billed per TB at published rates. IPv6 primary addresses are free; an IPv4 primary address costs €0.50/month (excl. VAT) as a standalone line item, though the current catalog's "price incl. IPv4" view folds it into the headline number. Backups and snapshots are paid extras, not inclusions (see below).

The ARM-specific value proposition is cores per euro. The entry CAX11 gives you 2 shared Ampere Altra vCPUs, 4GB RAM and 40GB NVMe; the CAX21 doubles that to 4 vCPUs, 8GB and 80GB. Both run at about 2GHz and, in third-party tracking data, cost meaningfully less than the x86 plans with comparable memory. The gap is not a rounding error — for scale-out workloads with many small containers, Arm is the cheapest way to buy Hetzner compute.

Two pricing caveats. First, the Cost-Optimized family's "proven hardware" policy means limited stock; the sibling CX23 listing showed as "not available" when we reviewed the page, and availability of specific CAX sizes can fluctuate. Second, everything here is shared vCPU: the cheap price buys burstable performance, not dedicated cores. If you need sustained CPU, Hetzner's dedicated-vCPU General Purpose line starts at €43.49/month and is x86-only as far as we can tell.

Performance & infrastructure

The silicon is Ampere Altra — the Neoverse-N1 core, arm64, roughly 2GHz, with ECC memory and local NVMe. These are proper server parts, not the Raspberry-Pi-class chips some "ARM VPS" listings use. In third-party benchmarks the small CAX plans show single-core scores in the same band as budget x86 instances and weaker memory bandwidth; where Arm wins is throughput per euro on parallel, cache-friendly work — web serving, reverse proxies, application servers, CI runners, build farms, container fleets.

The practical performance question is software, not hardware. By 2026 the arm64 ecosystem is broad: Nginx, Postgres, Redis, Node.js, Python, Go, Rust, Java, Docker's official images and the Kubernetes control plane all ship arm64 builds, and Hetzner's OS images and one-click apps explicitly support the Arm ecosystem. The laggards are some commercial agents (monitoring and security tooling), certain database extensions, older .NET workloads, and plenty of game-server binaries. Our rule: if your stack is open source and containerised, Arm is a non-event; if you depend on a vendor binary, check its download page before you migrate.

The architecture is also a boundary inside Hetzner itself. Their docs are explicit: you cannot rescale a server between architecture types, you cannot restore a backup or snapshot taken on x86 onto an Arm server (or the reverse), and ISO images must match the architecture. That is the single most important operational fact about this product line — Arm is not a switch you flip on an existing server, it is a parallel fleet you plan for.

Network and platform services are shared with the rest of Hetzner Cloud and are strong: firewalls, private networks, floating IPs, load balancers, volumes, placement groups, a documented REST API, Terraform and Ansible integrations. DDoS protection is automatic and free for all customers (Arbor and Juniper scrubbing hardware, pattern-based filtering), and the platform carries a 99.9% uptime promise with 24/7 support. Datacenter parks are ISO 27001 certified with BSI C5 attestation for the German sites. For CAX specifically, the current catalog lists EU locations (Nuremberg and Helsinki in the Cost-Optimized rows; Falkenstein is observed alongside them in third-party trackers) — unlike the x86 lines, the Arm plans are not currently advertised in Hetzner's US or Singapore regions.

We have not run our own sysbench, fio or iperf3 tests on CAX instances — our published numbers cover the x86 CX line — so we make no hands-on performance claim here beyond what public data shows.

Where it falls short

Architecture lock-in cuts both ways. Existing x86 workloads migrate to Arm only by rebuilding; snapshots, backups and rescale paths do not cross the boundary. Teams that treat Arm as an optimisation to toggle later will find it a migration project instead.

Availability is the second constraint. Moving CAX into the Cost-Optimized family with its limited-stock caveat, EU-only listing, and a smaller plan range than x86 makes the line feel like a specialist offering rather than a first-class citizen. The launch-era €3.79 pricing is also gone; today's entry price is higher, which narrows (but does not close) the gap with x86.

Then there is the usual shared-CPU honesty: vCPUs are shared, so a noisy neighbour can dent sustained throughput. And Arm's single-core performance remains modest — workloads that depend on one fast core (some application logic, many game servers, per-request latency budgets) will be happier on Hetzner's higher-frequency x86 options.

Finally, this is unmanaged infrastructure. No control panel beyond Hetzner's own console, no OS hardening service, no included backups. Hetzner's support is good and 24/7, but the machine is yours to run.

One pricing habit worth adopting here: because billing is hourly with a monthly cap, Arm fleets are cheap to experiment with. Spin up a CAX21, run your build pipeline against it for three days, measure real wall-clock savings, then delete it and pay for three days. The migration arithmetic stops being a spreadsheet exercise and becomes a cheap experiment — and that is the strongest argument for keeping a small Arm pilot running next to your x86 production fleet.

Who should pick this

Our pick for teams already containerised on open-source stacks who want the cheapest reliable European compute: web farms, API nodes, CI runners, staging environments, build machines, monitoring stacks, and anything scale-out where more small cores beat fewer fast ones. If you run Kubernetes or Docker Compose with arm64 images, CAX plans are the obvious cost lever.

It also suits individual developers and students priced out of x86 — the entry plan is one of the lowest-cost ways to run a real server in a real European datacenter with hourly billing.

Skip it if your software ships x86-only binaries, if you need sustained dedicated CPU, if you need US or Asian placement for the same plan, or if you want to convert an existing x86 server later. For general-purpose Hetzner Cloud, our standing recommendation is the x86 line covered in the main review; for raw comparisons, see /benchmarks and /category/vps-providers.

Key takeaways

• CAX plans are Hetzner Cloud's Arm64 line, built on Ampere Altra (Neoverse-N1) cores; launched April 2023 starting at €3.79/month.
• Today's catalog lists the entry CAX11 (2 vCPU, 4GB RAM, 40GB NVMe) from €6.49/month incl. IPv4 and the 16-vCPU CAX41 at €41.49/month, excl. VAT.
• 20TB included traffic in EU locations, free IPv6, €0.50/month IPv4, hourly billing with a monthly cap.
• Snapshots and backups are paid add-ons; DDoS protection is automatic and free for all customers.
• Architecture is a hard boundary: no rescaling or restoring between x86 and Arm servers — plan Arm as its own fleet.
• Best fit: containerised, open-source, scale-out workloads in Europe where price per core matters more than single-thread speed.

Sources

• https://hetzner.com/pressroom/arm64-cloud
• https://www.hetzner.com/cloud/
• https://www.hetzner.com/cloud/cost-optimized/
• https://docs.hetzner.com/cloud/servers/overview/
• https://docs.hetzner.com/cloud/servers/faq/
• https://docs.hetzner.com/cloud/servers/backups-snapshots/overview
• https://www.hetzner.com/unternehmen/ddos-schutz/
• https://sparecores.com/server/hcloud/cax11
• https://sparecores.com/server/hcloud/cax21