NIEK2-0193

① SA Source

Context Before

Source: SemiAnalysis AI Networking Model , Nvidia

In the Rubin Generation, Nvidia will offer the Rubin GPU in an Oberon NVL72 form factor with an all-copper scale-up network. For Rubin Ultra, as we expected, there will only be a copper scale-up option for Rubin Ultra in the Oberon and Kyber Rack form factor. Rubin Ultra will also be offered in a larger world size system that connects 8 Oberon Racks of 72 Rubin Ultra GPUs to form what will be referred to as NVL576. CPO scale-up will be used to build the larger world size, connecting between the racks in a two-tier all to all network, though scale-up inside the racks will remain copper-based.

Evidence

There is some disagreement on whether copper will still be used for scale-up within the rack or whether CPO will replace copper

Context After

Nvidia’s approach has been to use copper where they can, and optics where they must. The architecture of NVL1152 in the Feynman generation will follow the same principle. It is clear that the NVL1152 will adopt CPO to connect between racks, but from GPUs to NVLink Switches is currently copper POR. Nvidia is unable to achieve another doubling of electrical lane speed from 224Gbit/s bi-di to 448Gbit/s uni-di means bandwidth isn’t that amazing.

While 448G high speed SerDes have big challenges for shoreline, reach, and power versus using a die-to-die connection to an optical engine, the manufacturing challenges, cost, and reliability for Feynman necessitate using copper to the Switch.

② Atomic Claim

目前仍存在分歧:機櫃內 scale-up 究竟會繼續使用 copper,還是由 CPO 取代 copper

  • Epistemic Mode: ASSERTED
  • Mapping Status: PARTIAL

③ Semantic Frame

{
  "additional_nodes": [],
  "frame_type": "RELATION",
  "object": {
    "id": "04_knowledge_base/CPO",
    "label": "CPO"
  },
  "predicate": "USES",
  "qualifiers": {
    "condition_text": null,
    "numeric_mentions": [],
    "temporal_mentions": []
  },
  "subject": {
    "id": "04_knowledge_base/Copper",
    "label": "copper"
  }
}

④ Canonical Entity Mapping

RoleSurface LabelCanonical Target
subjectcopperCopper
objectCPOCPO

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。