# Where Sandboxes Run

> The hosts a managed sandbox runs on, what its CPU looks like from inside, and how fast it is.

**URL:** https://inference.sh/docs/extend/sandbox-hardware
**Last updated:** 2026-11-10

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The hosts a [managed sandbox](/docs/extend/managed-sandboxes) runs on, what its CPU looks like from inside, and how fast it is.

→ [Sandbox limits and pricing](/docs/extend/sandbox-limits) · [Inside a sandbox](/docs/extend/sandbox-environment) · [Sandboxes API](/docs/api/rest/sandboxes)

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## Hosts

Every sandbox is a Firecracker virtual machine on a physical server the platform runs. Today those are AMD servers: AMD Ryzen 9 9950X hosts and AMD EPYC hosts. You cannot choose the host; the placement shows on the sandbox (`engine_id`).

- **vCPUs are shared.** A sandbox's vCPUs are threads on the host, not cores set aside for it. Sandboxes on the same host share CPU time, so a busy host can make a run slower.
- **Memory is the sandbox's own.** The memory you ask for is reserved for the box while it runs.
- **No GPU.** Sandboxes have none.

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## The CPU from inside

The guest sees its vCPUs as one socket with one thread per core. `/proc/cpuinfo` names a generic `AMD EPYC` model, whatever the host is.

The guest gets every compute instruction the host has: on a 9950X host that includes AVX-512, VAES, VPCLMULQDQ and SHA. It does not see host-only features (power and frequency controls, performance counters, nested virtualization).

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## Performance

The V8 Web Tooling Benchmark, the Node.js workload of the [Phoronix Test Suite](https://openbenchmarking.org/test/pts/node-web-tooling) (`pts/node-web-tooling-1.0.1`), in one sandbox on a quiet AMD Ryzen 9 9950X host:

| Machine | Runs per second |
|---------|-----------------|
| Sandbox, 4 vCPUs, 8 GiB | 27.2–27.75 |
| The same host without a VM, all 32 threads | 30.2 |

Measured 2026-11-09: Node.js 22.23.1, Web Tooling Benchmark 0.5.3, 3 to 5 passes, median of each run's geometric mean. Higher is better.

A sandbox runs at about 90% of the bare host. On a host where many sandboxes are busy at once, each one is slower; the figure above is a quiet host.