SA260324R-0197
① SA Source
- Source: 開啟完整 SA 文章
- Section:
Nvidia’s CPO Roadmap - Line hint:
215
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
When we reach the Feynman Generation, CPO usage will expand via another large world size rack, the NVL1152 which is formed by combining 8 Kyber racks. While the Nvidia Technical Blog ↗ that outlines the rack configuration roadmap states that “NVIDIA Kyber will scale up into a massive all-to-all NVL1152 supercomputer using similar direct optical interconnects for rack-to-rack scale-up”, Jensen Huang in a Financial Analyst Q+A session did say that NVL1152 in Feynman would be “all CPO”. 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
目前對 rack 內 scale-up 到底會繼續使用 copper，還是由 CPO 取代 copper，存在不同說法。
- Epistemic Mode:
ASSERTED - Mapping Status:
COMPLETE
③ Semantic Frame
{
"comparison_expression": "rack 內 scale-up 是否繼續使用 copper，或改由 CPO 取代 copper，目前存在不同說法。",
"entities": [
{
"id": "04_knowledge_base/Copper",
"label": "copper"
},
{
"id": "04_knowledge_base/CPO",
"label": "CPO"
}
],
"frame_type": "COMPARISON",
"metric": "INTRA_RACK_SCALE_UP_TECHNOLOGY",
"operator": "UNCERTAIN_ALTERNATIVE",
"qualifiers": {
"condition_text": null,
"numeric_mentions": [],
"temporal_mentions": [
"目前"
]
}
}④ Canonical Entity Mapping
⑤ V2 Draft（需要修正時直接編輯）
Inline repair
只編輯以下三個 Draft 區塊。完成後將
review_action設為REQUEST_REPAIR，再手動執行 Repair Preview。
執行腳本前，Draft 不會寫入 Claim Store 或 Graph。
V2 Atomic Claim Draft
目前對 rack 內 scale-up 到底會繼續使用 copper，還是由 CPO 取代 copper，存在不同說法。
V2 Semantic Frame Draft
{
"comparison_expression": "rack 內 scale-up 是否繼續使用 copper，或改由 CPO 取代 copper，目前存在不同說法。",
"entities": [
{
"id": "04_knowledge_base/Copper",
"label": "copper"
},
{
"id": "04_knowledge_base/CPO",
"label": "CPO"
}
],
"frame_type": "COMPARISON",
"metric": "INTRA_RACK_SCALE_UP_TECHNOLOGY",
"operator": "UNCERTAIN_ALTERNATIVE",
"qualifiers": {
"condition_text": null,
"numeric_mentions": [],
"temporal_mentions": [
"目前"
]
}
}V2 Revision Metadata Draft
{
"epistemic_mode": "ASSERTED",
"mapping_status": "COMPLETE"
}⑥ 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。