Does a Cua Space start faster than an E2B sandbox?
On 2026-10-25, from the same Mac Studio and in the same minutes: a Cua Space running on the Mac ran its first command 234.6 ms after create, and an E2B sandbox reached over the internet 299 ms (p50; n = 30 and 30). The round trip to E2B's API was 14.5 ms minimum, 44.8 ms average.
Measured Build app 0.15.0, cua 0.9.0, cua-spacesd 0.8.0; E2B cloud, official E2B Python SDK e2b 2.59.0Raw data (CSV)
Results
Time from the create call until the first command returns, one sandbox at a time. Lower is better.
- Cua Spaces (This Mac)
- E2B
| Result | Value | Fastest | p50 | p90 | p99 | Slowest | n | Measured |
|---|---|---|---|---|---|---|---|---|
| Cua Spaces (This Mac) | 234.6 ms p50 | 204.8 ms | 234.6 ms | 257.7 ms | 270.1 ms | 270.1 ms | 30 | 2026-10-25 |
| E2B | 299 ms p50 | 195.5 ms | 299 ms | 417.2 ms | 877.8 ms | 877.8 ms | 30 | 2026-10-25 |
Method: Cua Spaces (This Mac)
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 gVisor container in the built-in Linux runtime VM (Lima on Virtualization.framework, default 4 vCPU / 32 GiB) Space created from ghcr.io/trycua/linux:24.04-slim with --kind container --runtime gvisor --cpus 1 --memory-mb 1024 --headless (only cua-spacesd in the guest, no desktop).
Each 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: 13014 ms).
Caveats
- Headless shape (only cua-spacesd).
- Golden snapshots on (the default): the excluded first create records the snapshot that later creates restore.
- Measured on the Mac itself: no network between the client and the Space.
Environment and build
| Machine | Mac Studio, Mac14,13 (Mac Studio) |
|---|---|
| Chip | Apple M2 Max, 12 cores |
| Memory | 96 GB |
| OS | macOS 26.6.2 (25G83) |
| Where | local |
| Kind | gvisor |
| Image | ghcr.io/trycua/linux:24.04-slim |
| Shape | 1 vCPU, 1 GiB, --headless |
| Other vms | 2 |
| Network | n/a (local) |
| Settings | CUA_POOL_AUTO=off (no warm pool); golden snapshots at their default (on) |
| Build | 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 |
| App | 0.15.0 |
| cua | 0.9.0 |
| cua_spacesd | 0.8.0 |
Reproduce
# On an Apple silicon Mac (macOS 26), with Rust (rustup) and git:
curl -fLO https://github.com/trycua/cua/releases/download/cua-spaces-v0.15.0/cua-spaces-0.15.0-darwin-universal.dmg
hdiutil attach -nobrowse -mountpoint /tmp/cua-dmg cua-spaces-0.15.0-darwin-universal.dmg
mkdir -p ~/bench && ditto "/tmp/cua-dmg/Cua Spaces.app" ~/bench/"Cua Spaces.app" && hdiutil detach /tmp/cua-dmg
git clone --depth 1 --branch cua-spaces-v0.15.0 https://github.com/trycua/cua ~/bench/cua
(cd ~/bench/cua/libs/cua && cargo build --locked --release -p cua-sdk --example rollout_bench --example channel_bench)
export PATH="$HOME/bench/Cua Spaces.app/Contents/MacOS:$PATH" CUA_HOME=~/bench/home DO_NOT_TRACK=1 CUA_TELEMETRY=0
RB=~/bench/cua/libs/cua/target/release/examples/rollout_bench
cua daemon start --foreground & # with CUA_POOL_AUTO=off in its environment
IMG=ghcr.io/trycua/linux:24.04-slim
$RB create --prefix warm- --n 1 --image $IMG --kind container --runtime gvisor --cpus 1 --memory-mb 1024 --headless # excluded warm-up
$RB create --prefix cold- --n 30 --conc 1 --image $IMG --kind container --runtime gvisor --cpus 1 --memory-mb 1024 --headless # one JSON line per sample (ready_ms)Method: E2B
Driver on the Mac (same host, same minutes as the Cua run): e2b_bench.py cold --n 30 --conc 1 with the official E2B Python SDK. Each sample = AsyncSandbox.create() start → sandbox.commands.run("true") returns exit 0 (create + first exec), serial, each sandbox killed after its sample. Includes the internet round trips from the Mac to E2B (us-west1); Cua's numbers are on the same machine with no network hop, so this compares what a client on this Mac sees, not E2B's in-region create time. Run right after the Cua gVisor serial run, 2026-10-25 ~00:44 UTC.
Caveats
- Different network paths: E2B is reached over the internet from the Mac (E2B region GCP us-west1); the Cua Space runs on the Mac.
- E2B's base template is 2 vCPU and 512 MiB; the Cua Space is 1 vCPU and 1 GiB, headless.
- This is what a client on this Mac sees, not E2B's in-region create time.
Environment and build
| Machine | Mac Studio, Mac14,13 (Mac Studio) |
|---|---|
| Chip | Apple M2 Max, 12 cores |
| Memory | 96 GB |
| OS | macOS 26.6.2 (25G83) |
| Where | local |
| Kind | e2b-cloud |
| Image | E2B default base template |
| E2b region | GCP us-west1 (The Dalles, Oregon; ipinfo from inside a sandbox, 2026-10-25) |
| Network | home internet from the Mac; ICMP RTT to api.e2b.app (34.102.227.47) min/avg/max 14.5/44.8/139.4 ms (10 pings, 2026-10-25 00:43 UTC) |
| Other vms | 2 |
| Build | E2B cloud, official E2B Python SDK e2b 2.59.0 |
Reproduce
python3 -m venv e2b-venv && e2b-venv/bin/pip install e2b==2.59.0 httpx
curl -fLO https://cua.ai/benchmarks/spaces-vs-e2b-cold-start/files/e2b_bench.py
export E2B_API_KEY=... # your key
e2b-venv/bin/python e2b_bench.py cold --n 30 --conc 1 --label cold30Helper scripts: e2b_bench.py.
Cua commands use the published Cua Spaces 0.15.0 release and the public trycua/cua repository at the tag cua-spaces-v0.15.0. Downloads: samples (CSV), result (JSON), this page as Markdown.
Questions
Is this a fair comparison?
It compares what a client on this Mac sees. The Cua Space ran on the Mac itself; E2B was reached over the internet from the same Mac, in the same minutes. A client inside E2B's region would see a shorter E2B time. The shapes differ too: E2B's base template has 2 vCPU and 512 MiB, the Cua Space 1 vCPU and 1 GiB.
Where do the E2B sandboxes run?
In E2B's GCP us-west1 region, read from inside a sandbox on the day.
Can I run this myself?
Yes. The Cua side uses the published Cua Spaces 0.15.0 release and the public trycua/cua repository at the tag cua-spaces-v0.15.0; the other side uses the vendor's official Python SDK and the script linked under Reproduce. You need your own account and API key for the vendor.
Checked 2026-10-25. Sources: the samples and result files above, measured by Cua. Cua Spaces and hosted sandboxes.