{
  "slug": "microvm-cold-start-mac",
  "question": "How fast does a microVM Space start on a Mac?",
  "answer": "A new headless microVM Space (one Virtualization.framework VM per Space) ran its first command 341.1 ms after create (p50, n = 30) on a Mac Studio (Apple M2 Max, 96 GB), measured 2026-10-25 on Cua Spaces 0.15.0.",
  "status": "measured",
  "url": "https://cua.ai/benchmarks/microvm-cold-start-mac",
  "csv": "https://cua.ai/benchmarks/microvm-cold-start-mac.csv",
  "markdown": "https://cua.ai/benchmarks/microvm-cold-start-mac.md",
  "group": "Start",
  "current": {
    "run": "2026-10-25",
    "schema": "cua.bench-result/v1",
    "bench": "spaces-startup.microvm",
    "slug": "microvm-cold-start-mac",
    "metric": "create_to_first_exec_ms",
    "value": 341.1,
    "unit": "ms",
    "stat": "p50",
    "n": 30,
    "percentiles": {
      "p50": 341.1,
      "p90": 349,
      "p95": 352.1,
      "p99": 359.9,
      "min": 323.2,
      "max": 359.9
    },
    "extra": {
      "first_create_ms": 435,
      "failed": 0
    },
    "samples_csv": "samples.csv",
    "measured_at": "2026-10-25T00:45:00Z",
    "build": {
      "cua": "0.9.0",
      "cua_spacesd": "0.8.0",
      "app": "0.15.0",
      "source": "Cua Spaces 0.15.0 DMG (https://github.com/trycua/cua/releases/download/cua-spaces-v0.15.0/cua-spaces-0.15.0-darwin-universal.dmg, sha256 8725a09ba4132aa8a1667fa48c86416c91d5dec0d3c7dc93f88f5f3e29e0aba0): bundled cua 0.9.0, Helpers/cua-spacesd 0.8.0, cua-vz",
      "published": true,
      "harness": "built from tag cua-spaces-v0.15.0 (709b18d9ee) on the host: cargo build --release -p cua-sdk --example rollout_bench --example channel_bench (Rust 1.97.1)"
    },
    "host": {
      "name": "Mac Studio",
      "model": "Mac14,13 (Mac Studio)",
      "chip": "Apple M2 Max",
      "cpus": 12,
      "memory_gb": 96,
      "os": "macOS 26.6.2 (25G83)",
      "where": "local"
    },
    "environment": {
      "kind": "microvm",
      "image": "ghcr.io/trycua/linux:24.04-slim",
      "shape": "1 vCPU, 1 GiB, --headless",
      "load_avg_before": [
        2.51,
        1.83,
        1.51
      ],
      "other_vms": 2,
      "network": "n/a (local)",
      "settings": "CUA_POOL_AUTO=off (no warm pool); golden snapshots at their default (on)"
    },
    "method": "Driver on the host: `rollout_bench create` (Rust SDK example built from the release tag) talks to this release's own `cua daemon` (isolated CUA_HOME). Workload: a microVM, runtime vz (cua-vz, Virtualization.framework, one VM per Space, guest kernel 6.1.155) Space created from ghcr.io/trycua/linux:24.04-slim with `--kind microvm --cpus 1 --memory-mb 1024 --headless` (only cua-spacesd in the guest, no desktop).\n\nEach sample = `SandboxCreateOptions` create call start → the Space's cua-spacesd answers a first `sh -c true` with exit 0 (create + attach + first exec). n=30, serial (one at a time), each Space deleted after its sample. The warm pool is off (`CUA_POOL_AUTO=off`), so every sample is a real create. One warm-up create before the samples is excluded (image pull/unpack and the golden snapshot it records: 435 ms).",
    "reproduce": "# On an Apple silicon Mac (macOS 26), with Rust (rustup) and git:\ncurl -fLO https://github.com/trycua/cua/releases/download/cua-spaces-v0.15.0/cua-spaces-0.15.0-darwin-universal.dmg\nhdiutil attach -nobrowse -mountpoint /tmp/cua-dmg cua-spaces-0.15.0-darwin-universal.dmg\nmkdir -p ~/bench && ditto \"/tmp/cua-dmg/Cua Spaces.app\" ~/bench/\"Cua Spaces.app\" && hdiutil detach /tmp/cua-dmg\ngit clone --depth 1 --branch cua-spaces-v0.15.0 https://github.com/trycua/cua ~/bench/cua\n(cd ~/bench/cua/libs/cua && cargo build --locked --release -p cua-sdk --example rollout_bench --example channel_bench)\nexport PATH=\"$HOME/bench/Cua Spaces.app/Contents/MacOS:$PATH\" CUA_HOME=~/bench/home DO_NOT_TRACK=1 CUA_TELEMETRY=0\nRB=~/bench/cua/libs/cua/target/release/examples/rollout_bench\ncua daemon start --foreground &   # with CUA_POOL_AUTO=off in its environment\nIMG=ghcr.io/trycua/linux:24.04-slim\n$RB create --prefix warm- --n 1 --image $IMG --kind microvm --cpus 1 --memory-mb 1024 --headless   # excluded warm-up\n$RB create --prefix cold- --n 30 --conc 1 --image $IMG --kind microvm --cpus 1 --memory-mb 1024 --headless   # one JSON line per sample (ready_ms)",
    "caveats": [
      "Headless shape (only cua-spacesd); the full desktop image starts slower.",
      "Golden snapshots on (the default): the excluded first create records the snapshot that later creates restore.",
      "A start without the golden snapshot was not measured."
    ],
    "sources": [],
    "status": "measured"
  },
  "earlier": []
}