SA260324R-0281
① SA Source
- Source: 開啟完整 SA 文章
- Section:
Vera ETL256 - Line hint:
348
Context Before
The Vera standalone rack addresses this directly, achieving unprecedented density by fitting 256 CPUs into a single rack — a feat that necessitates liquid cooling. The underlying rationale mirrors the NVL rack design philosophy: pack compute tightly enough that copper interconnects can reach everything within the rack, eliminating the need for optical transceivers on the spine.
Evidence
The cost savings from copper more than offset the additional cooling overhead.
Context After
Each Vera ETL rack consists of 32 compute trays, 16 above and 16 below, arranged symmetrically around four 1U MGX ETL switch trays (based on Spectrum-6) in the middle. The symmetric split is deliberate: it minimizes cable length variance between compute trays and the spine, keeping all connections within copper reach. From each switch tray, rear-facing ports connect to that copper spine for intra-rack communication, while 32 front-facing OSFP cages provide optical connectivity to the rest of the POD.
② Atomic Claim
copper 帶來的成本節省，超過額外 cooling overhead。
- Epistemic Mode:
ASSERTED - Mapping Status:
PARTIAL
③ Semantic Frame
{
"attribute": "COST_TRADEOFF",
"context_nodes": [],
"entity": {
"id": "04_knowledge_base/Copper",
"label": "copper"
},
"frame_type": "ATTRIBUTE",
"qualifiers": {
"condition_text": "cooling overhead has no canonical entity",
"numeric_mentions": [],
"temporal_mentions": []
},
"value": {
"numeric_mentions": [],
"value_text": "copper 的成本節省超過額外 cooling overhead。"
}
}④ Canonical Entity Mapping
| Role | Surface Label | Canonical Target |
|---|---|---|
| entity | copper | Copper |
⑤ Human Review
請在 Properties 逐項確認：
- 原文 → Atomic Claim 是否忠實
- Atomic Claim → Semantic Frame 是否忠實
- Canonical Entity mapping 是否正確
- Epistemic mode 是否保留原文語氣
- 最後選擇
review_action
Review state
Markdown 內文不是正式 approval。只有 Apply bridge 寫入的 Decision Ledger event 才是正式決策。