{
 "schema_version": "1.7.0",
 "id": "x_NXMC-2024-0148",
 "modified": "2026-10-19T02:33:38.839Z",
 "published": "2026-10-18T09:00:52.565Z",
 "summary": "Llama-3.1-405B-FP8: structural change at d79e67b (2024-08-14)",
 "details": "Llama-3.1-405B-FP8: KV heads 16 to 8; derived parameters 410.08B to 405.85B (-4.23B, -8.46 GB of bf16 weights) (2024-08-14).\n\nRepository: https://huggingface.co/meta-llama/Llama-3.1-405B-FP8. Revisions from d79e67b5ee26735510cff4fb9ec10fb74fadb8c1 onward carry this change; a pin at 60db52617fa6b1d8ad96b37f6e6bcc172b6f6846 or earlier does not.\n\nChanged keys:\n- num_key_value_heads: 16 -> 8 (structural)\n\nThis record says what the change does mechanically. It is not a report that anything broke for anyone.",
 "affected": [
  {
   "ranges": [
    {
     "type": "GIT",
     "repo": "https://huggingface.co/meta-llama/Llama-3.1-405B-FP8",
     "events": [
      {
       "introduced": "d79e67b5ee26735510cff4fb9ec10fb74fadb8c1"
      }
     ]
    }
   ],
   "database_specific": {
    "model": "meta-llama/Llama-3.1-405B-FP8",
    "previous_revision": "60db52617fa6b1d8ad96b37f6e6bcc172b6f6846"
   }
  }
 ],
 "references": [
  {
   "type": "INTRODUCED",
   "url": "https://huggingface.co/meta-llama/Llama-3.1-405B-FP8/commit/d79e67b5ee26735510cff4fb9ec10fb74fadb8c1"
  },
  {
   "type": "PACKAGE",
   "url": "https://huggingface.co/meta-llama/Llama-3.1-405B-FP8"
  },
  {
   "type": "WEB",
   "url": "https://www.neurarch.com/changes-feeds/models/meta-llama/Llama-3.1-405B-FP8.html"
  }
 ],
 "database_specific": {
  "source": "neurarch model change tracker",
  "model": "meta-llama/Llama-3.1-405B-FP8",
  "kind": "structural",
  "classes": [
   "structural"
  ],
  "changed_keys": [
   {
    "file": "config",
    "key": "num_key_value_heads",
    "before": 16,
    "after": 8,
    "class": "structural"
   }
  ],
  "impact": {
   "memory": true,
   "serving": true,
   "tokenizer": false,
   "licence": null
  },
  "breaking": true,
  "breaking_rule": "https://www.neurarch.com/changes-feeds/advisories/index.json#breaking_rule",
  "consequence": {
   "params": {
    "before": 410081375488,
    "after": 405853517056
   },
   "weightsGbBf16": {
    "before": 820.163,
    "after": 811.707
   },
   "trainPeakGb": {
    "before": 12982.474,
    "after": 12855.976
   },
   "fingerprint": null,
   "context": null,
   "eos": null,
   "bos": null
  },
  "commit_date": "2024-08-14T13:27:04.000Z",
  "detected_at": "2026-10-18T09:00:52.565Z",
  "detected_by": "backfill",
  "days_since_first_commit": 25,
  "license": "CC-BY-4.0"
 }
}