VR2R-0320
① SA Source
- Source: 開啟完整 SA 文章
- Section:
PCB vs Flyover Cables - Line hint:
284
Context Before
Another factor that affects signal performance is cross-talk. Given the increase in the number of I/Os per GPU, lane density in the PCB also increases. Cross-talk describes the scenario where the copper traces are too close to each other and the signal from one lane affects the signal in a neighboring lane. Some copper traces are designed for power as well. When the power lanes are too close to the signal lanes, noise from the power lanes can also modulate the signal as well.
Evidence
In conclusion, insertion loss scales with signal frequency, and high-speed signal suffers more insertion loss from PCB than from fly over cables.
Context After
Hence, as traditional CPU servers upgrade to higher signaling frequencies such as upgrading to newer PCIe generations, the CPU server design increases the adoption of fly over cables to compensate for insertion loss from the PCB.
② Atomic Claim
總結而言，insertion loss 會隨 signal frequency 增加，而且 high-speed signal 在 PCB 上承受的 insertion loss 高於 flyover cables。
- Epistemic Mode:
ASSERTED - Mapping Status:
PARTIAL
③ Semantic Frame
{
"attribute": "INSERTION_LOSS_VS_FLYOVER_CABLE",
"context_nodes": [],
"entity": {
"id": "04_knowledge_base/PCB",
"label": "PCB"
},
"frame_type": "ATTRIBUTE",
"qualifiers": {
"condition_text": "flyover cables are plain text in source claim",
"numeric_mentions": [],
"temporal_mentions": []
},
"value": {
"numeric_mentions": [],
"value_text": "insertion loss scales with signal frequency and is higher on PCB than on flyover cables for high-speed signals."
}
}④ Canonical Entity Mapping
| Role | Surface Label | Canonical Target |
|---|---|---|
| entity | PCB | PCB |
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。