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CLI: probe

GPU discovery and real-time telemetry. Enumerates GPU devices via the hwledger-probe crate (NVIDIA → AMD → Metal → Intel). JSON output is stable-schema (hwledger.v1) and suitable for downstream fleet ingestion.

What you'll see

Running hwledger probe displays:

  • Each GPU's index, model name, VRAM (total and free)
  • Compute capability / architecture (e.g. CUDA compute 8.9 for RTX 4090)
  • Current memory utilization and temperature
  • Driver version (NVIDIA) or ROCm version (AMD)

Watch as the probe detects your hardware in real-time. On multi-GPU boxes, you'll see each device listed separately.

Journey not yet recorded.

Run the journey recorder to capture interactions:

./apps/macos/HwLedgerUITests/scripts/run-journeys.sh

What to watch for

  • GPU order: Index 0, 1, 2... maps to CUDA_VISIBLE_DEVICES
  • Memory free: Critical for planning (if 0 GB free, model won't fit)
  • Compute capability: Determines supported attention variants (older GPUs may not support newest optimizations)
  • Temperature: Shows if GPU is thermally constrained
  • Multi-GPU layout: Bandwidth between GPUs affects tensor parallelism efficiency

Next steps

Reproduce

bash
# List GPUs (human-readable)
hwledger probe

# List as JSON (for scripting)
hwledger probe --json | jq '.gpus[] | {name, vram_free_gb}'

# Watch continuously
hwledger probe --watch

Source

Recorded journey tape on GitHub

Released under the Apache 2.0 License.