# ComfyUI ComfyUI 0.42.0 (commit cdf272f), PyTorch 2.14.1 CPU: our test log

Canonical: https://theagenticweekly.com/tests/comfyui · Last verified: 2026-10-26 · Published: 2026-10-26 · Author: Agentic Weekly (operated independently from Texas, US) · Evidence: Tested by us on 2026-10-26. Local open-weight model, not the vendor's hosted models. A smoke test on a CPU-only box, not a benchmark.

> ComfyUI 0.42.0 installed in 17.42 s and its CPU-only server was ready in 30.1 s with 1014 node types, but we did not generate an image.

## Result at a glance

Table: ComfyUI test record

| Field | Value |
|---|---|
| Result | Passed |
| Version tested | ComfyUI 0.42.0 (commit cdf272f), PyTorch 2.14.1 CPU |
| Date and time | 2026-10-26, 10:40 CDT (America/Chicago) |
| Task | Clone ComfyUI, install it into a fresh Python 3.12 environment with the CPU build of PyTorch, start the server with --cpu, and query /system_stats and /object_info. Pass means the server starts without a GPU and reports its nodes. No checkpoint was downloaded and no image was generated. |
| Model used | none (no image model loaded) |
| Hardware | Linux x86_64 virtual machine (Debian 13), 8 vCPU (Intel Xeon, 1 thread per core), 15 GiB RAM, no GPU |
| Install | 17.42 s, 2193 MB |
| Time to ready | 30.1 s |
| Node types | 1014 |

## What we found

- The server reported ComfyUI 0.42.0 on a single CPU device and PyTorch 2.14.1+cpu.
- /object_info listed 1014 node types in 0.31 s, including KSampler, CLIPTextEncode, CheckpointLoaderSimple, VAEDecode and SaveImage.
- The checkpoint list was empty because we installed no model files.

## What we ran, step by step

Table: Commands run, wall-clock time and exit code

| Step | Wall time | Exit code | Notes |
|---|---|---|---|
| Clone repository | 2.33 s | 0 | Shallow clone, commit cdf272f. |
| Install with uv (cold, no cache) | 17.42 s | 0 | 2193 MB on disk including the CPU PyTorch build (2.14.1+cpu). Load 18.69. |
| Task command (start server, probe API) | 32.68 s | 0 | Ready after 30.1 s on a shared machine (load 18.42). |

Exact commands (paths shortened)

```
# Clone repository
git clone --depth 1 https://github.com/comfyanonymous/ComfyUI.git

# Install with uv (cold, no cache)
uv pip install torch torchvision torchaudio (CPU wheels) && uv pip install -r requirements.txt

# Task command (start server, probe API)
python main.py --cpu --listen 127.0.0.1 --port 8189 (driven by tasks3/comfy_task.py)
```

## Raw output (excerpts)

Probe results

```
{
 "ready_s": 30.1,
 "system_stats": {
  "comfyui_version": "0.42.0",
  "python_version": "3.12.15 (main, Oct 21 2026, 17:47:06) [Clang 23.1.3 ]",
  "pytorch_version": "2.14.1+cpu",
  "ram_total": 16779640832
 },
 "devices": [
  [
   "cpu",
   "cpu"
  ]
 ],
 "object_info_s": 0.31,
 "node_types": 1014,
 "sample_nodes": [
  "KSampler",
  "CheckpointLoaderSimple",
  "CLIPTextEncode",
  "SaveImage",
  "VAEDecode"
 ],
 "checkpoints_listed": []
}
```

The task script (tasks3/comfy_task.py)

```
import subprocess, time, json, urllib.request, sys, os, signal
PY = "/workspace/tests2/work/py/comfyui/bin/python"
cwd = "/workspace/tests2/work/comfy/ComfyUI"
t0 = time.time()
p = subprocess.Popen([PY, "main.py", "--cpu", "--listen", "127.0.0.1", "--port", "8189", "--disable-auto-launch"], cwd=cwd, stdout=open("/workspace/tests2/logs/comfy-server.log", "w"), stderr=subprocess.STDOUT)
def get(path):
    return json.load(urllib.request.urlopen("http://127.0.0.1:8189" + path, timeout=30))
res = {}
try:
    for i in range(240):
        try:
            st = get("/system_stats"); res["ready_s"] = round(time.time() - t0, 1); break
        except Exception:
            time.sleep(1)
    else:
        raise SystemExit("server never became ready")
    res["system_stats"] = {k: st["system"].get(k) for k in ("comfyui_version", "python_version", "pytorch_version", "ram_total")}
    res["devices"] = [(d["name"], d["type"]) for d in st["devices"]]
    t1 = time.time(); oi = get("/object_info"); res["object_info_s"] = round(time.time() - t1, 2)
    res["node_types"] = len(oi)
    res["sample_nodes"] = [n for n in ("KSampler", "CheckpointLoaderSimple", "CLIPTextEncode", "SaveImage", "VAEDecode") if n in oi]
    res["checkpoints_listed"] = oi["CheckpointLoaderSimple"]["input"]["required"]["ckpt_name"][0]
finally:
    p.send_signal(signal.SIGINT)
    try: p.wait(20)
    except Exception: p.kill()
print("RESULT_JSON " + json.dumps(res))
```

## Gotchas and things that broke

- Nothing useful can be generated until you add a checkpoint; the common Stable Diffusion files are multiple gigabytes.
- The full install, with PyTorch, is about 2.2 GB.

## What we did not test

- Generating any image: no checkpoint was downloaded (the SD-Turbo file we considered is 5.2 GB, and the machine's free memory could not hold it).
- GPU use, custom nodes, the ComfyUI Manager, workflows from the web interface, and the browser UI.
- Speed of image generation on CPU or on a GPU.

## Reproduce it

Versions change. These commands install whatever is latest on the day you run them unless a version is pinned, so expect different results later. The version we measured is in the table above.

```
git clone https://github.com/comfyanonymous/ComfyUI && cd ComfyUI
uv venv -p 3.12 .venv && VIRTUAL_ENV=.venv uv pip install torch torchvision torchaudio --extra-index-url https://download.pytorch.org/whl/cpu && VIRTUAL_ENV=.venv uv pip install -r requirements.txt
.venv/bin/python main.py --cpu --port 8189
curl http://127.0.0.1:8189/system_stats
```

## How to read this test

Every number on this page was measured on this one machine, which also ran other jobs, so timings are indicative and vary run to run. A pass means our small task worked once or as stated, a fail means it did not work as we ran it; neither says how the tool behaves with a vendor's frontier model, on a GPU, or at scale. Where a tool could not run without an account or a GPU, we say so instead of guessing.

See the [testing rig](https://theagenticweekly.com/methodology#testing-rig) for the hardware, the local model and the rules we follow, and the [test hub](https://theagenticweekly.com/tests) for every other test.

## FAQ

### Does ComfyUI start without a GPU?

Yes: with --cpu the server was ready in 30.1 s on an 8-core CPU-only machine and listed 1014 nodes. We did not generate an image.

## Sources

- [ComfyUI repository](https://github.com/comfyanonymous/ComfyUI) (fetched 2026-10-26)

## Related

- [All test logs](https://theagenticweekly.com/tests)
- [Methodology and testing rig](https://theagenticweekly.com/methodology#testing-rig)
- [ComfyUI facts and sources](https://theagenticweekly.com/tools/comfyui)

## How to cite

Agentic Weekly, "ComfyUI ComfyUI 0.42.0 (commit cdf272f), PyTorch 2.14.1 CPU: our test log", last updated 2026-10-26, https://theagenticweekly.com/tests/comfyui