{
  "slug": "file-transfer-throughput",
  "question": "How fast do files move into and out of a Space?",
  "answer": "Uploading one 100 MiB file into a running QEMU Linux VM Space ran at 625.7 MiB/s and downloading it at 873.3 MiB/s (p50 time, n = 10) 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/file-transfer-throughput",
  "csv": "https://cua.ai/benchmarks/file-transfer-throughput.csv",
  "markdown": "https://cua.ai/benchmarks/file-transfer-throughput.md",
  "group": "Density and throughput",
  "current": {
    "run": "2026-10-25",
    "schema": "cua.bench-result/v1",
    "bench": "channel.qemu",
    "slug": "file-transfer-throughput",
    "metric": "upload_100MiB_MiBps",
    "value": 625.7,
    "unit": "MiB/s",
    "stat": "p50",
    "n": 10,
    "percentiles": {
      "p50": 625.7
    },
    "extra": {
      "download_100MiB_MiBps_p50": 873.3,
      "upload_100MiB_ms_p50": 159.818,
      "upload_100MiB_ms_p95": 182.472,
      "download_100MiB_ms_p50": 114.51,
      "download_100MiB_ms_p95": 119.536,
      "upload_1MiB_ms_MiBps_p50": 211.1,
      "download_1MiB_ms_MiBps_p50": 148.8,
      "upload_4MiB_ms_MiBps_p50": 402.7,
      "download_4MiB_ms_MiBps_p50": 378.4,
      "upload_16MiB_ms_MiBps_p50": 509.9,
      "download_16MiB_ms_MiBps_p50": 549.2,
      "upload_512MiB_ms_MiBps_p50": 619.3,
      "download_512MiB_ms_MiBps_p50": 1164.1,
      "stream_stdout_MiBps": 169
    },
    "samples_csv": "samples.csv",
    "measured_at": "2026-10-25T01:12:51Z",
    "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": {
      "load_avg_before": [
        1.32,
        4.84,
        9.88
      ],
      "other_vms": 1,
      "network": "n/a (local)",
      "kind": "vm",
      "image": "linux (catalog alias, full Linux VM disk)",
      "shape": "2 vCPU, 2 GiB"
    },
    "method": "Driver on the host: `bench/channel/run.sh` from tag cua-spaces-v0.15.0 with `channel_bench` (Rust SDK example built from the tag). It creates one Linux VM Space on this Mac (`cua spaces create linux --on local --kind vm --cpus 2 --memory-mb 2048`, QEMU on HVF), measures it through the SDK and deletes it. Route: `local 127.0.0.1` (gRPC to the Space's cua-spacesd). Exec: 300 serial round trips each of a no-op RPC, `true` run directly, and `sh -c` (5 warm-up calls excluded). Files: one file per transfer of 1 MiB (n=20), 4 MiB (20), 16 MiB (10), 100 MiB (10), 512 MiB (5), upload then download, MiB/s = size / p50 time; files of 2 MiB and more use the VM's bulk lane (a shared disk, SHA-256 checked). channel_bench writes percentiles per metric, not per sample, so samples.csv holds one row per metric.",
    "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 &\ncd ~/bench/cua/libs/cua\nCUA=cua BENCH=target/release/examples/channel_bench FILES=1:20,4:20,16:10,100:10,512:5 OUT=results \\\n  bash bench/channel/run.sh bench/channel/baselines/macos-m2max-qemu.json",
    "caveats": [
      "Same machine (loopback): a client on another machine adds its network.",
      "Files of 2 MiB and more use the VM's bulk lane, a shared disk; every transfer is SHA-256 checked.",
      "samples.csv has one row per metric (percentiles), not one per sample."
    ],
    "sources": [],
    "status": "measured"
  },
  "earlier": []
}