{
  "host": "Apple M1 Pro / 16 GiB, macOS, Swift debug executable zimage-validate",
  "metalAPIValidation": true,
  "runtimeTests": "16 ZImageRuntime package tests passed with MTL_DEBUG_LAYER=1, including ComfyUI beta (alpha=beta=0.6) sigmas for shift 3 and 3.5 at 4-12 steps",
  "conversionSeconds": 46.23,
  "runs": [
    {
      "file": "native-896x1152.png",
      "width": 896,
      "height": 1152,
      "steps": 4,
      "seed": 1729,
      "sampler": "Euler",
      "scheduler": "beta",
      "shift": 3.5,
      "elapsedSeconds": 128.35,
      "peakMLXBytes": 4760601834,
      "preparationCounts": [
        0,
        1,
        2
      ],
      "previewCount": 4,
      "previewSize": [
        99,
        128
      ]
    },
    {
      "file": "native-1024.png",
      "width": 1024,
      "height": 1024,
      "steps": 4,
      "seed": 42,
      "sampler": "Euler",
      "scheduler": "beta",
      "shift": 3.5,
      "elapsedSeconds": 127.72,
      "peakMLXBytes": 4769023210,
      "preparationCounts": [
        0,
        1,
        2
      ],
      "previewCount": 4,
      "previewSize": [
        128,
        128
      ]
    },
    {
      "file": null,
      "width": 896,
      "height": 1152,
      "steps": 6,
      "seed": 1729,
      "sampler": "Euler",
      "scheduler": "beta",
      "shift": 3.5,
      "elapsedSeconds": 183.05,
      "peakMLXBytes": 4760601834,
      "preparationCounts": [
        0,
        1,
        2
      ],
      "previewCount": 6,
      "previewSize": [
        99,
        128
      ]
    }
  ],
  "review": "All three renders visually reviewed: coherent anatomy, hands, fabric and backgrounds; six steps is slightly softer than four.",
  "note": "Mac Debug timings with Metal validation; not iPhone timings. Physical iPhone validation pending."
}