SA260324R-0149
① SA Source
- Source: 開啟完整 SA 文章
- Section:
LPX Compute Tray - Line hint:
167
Context Before
Source: SemiAnalysis Networking Model ↗
Evidence
Something interesting about the system is the important role the FPGAs play. Nvidia refers to the FPGAs as “Fabric Expansion Logic” which serves multiple purposes. First, they act as a NIC which converts the LPU’s C2C protocol into Ethernet to connect to the Spectrum-X based ethernet scale-out fabric. It is this scale-out fabric through which the LPUs connect to GPUs in the decode system.
Context After
Second, the LPUs also traverse through the FPGAs to reach the host CPU, with the FPGAs converting C2C to PCIe to the CPU.
Third, the FPGAs are connected to the backplane to talk to other FPGAs in the node, we believe this is to help manage control flow and timing of all the LPUs. The FPGAs also bring extra system DRAM of up to 256GB each. This pool of memory can be used for KVCache if the user wants the entire decode process served by the LPX.
② Atomic Claim
首先，這些 FPGA 會充當 NIC，把 LPU 的 C2C protocol 轉成 Ethernet，以連接到以 Spectrum-X 為基礎的 Ethernet scale-out fabric。
- Epistemic Mode:
ASSERTED - Mapping Status:
PARTIAL
③ Semantic Frame
{
"frame_type": "NARY_RELATION",
"participants": [
{
"node": {
"id": "04_knowledge_base/FPGA",
"label": "FPGA"
},
"role": "fabric_expansion_logic"
},
{
"node": {
"id": "04_knowledge_base/NIC",
"label": "NIC"
},
"role": "network_interface_role"
},
{
"node": {
"id": "04_knowledge_base/Groq LPU",
"label": "LPU"
},
"role": "source_device"
},
{
"node": {
"id": "04_knowledge_base/Chip-to-Chip Interconnect",
"label": "C2C"
},
"role": "source_protocol"
},
{
"node": {
"id": "04_knowledge_base/Ethernet",
"label": "Ethernet"
},
"role": "destination_protocol"
}
],
"qualifiers": {
"condition_text": "Spectrum-X 在此 claim 沒有 canonical mapping；FPGA 主詞由緊鄰前文的 Fabric Expansion Logic 指涉解析",
"numeric_mentions": [],
"temporal_mentions": []
},
"relation_type": "CONVERTS_C2C_TO_ETHERNET_FOR_SCALEOUT"
}④ Canonical Entity Mapping
| Role | Surface Label | Canonical Target |
|---|---|---|
| fabric_expansion_logic | FPGA | FPGA |
| network_interface_role | NIC | NIC |
| source_device | LPU | 04_knowledge_base/Groq LPU |
| source_protocol | C2C | 04_knowledge_base/Chip-to-Chip Interconnect |
| destination_protocol | Ethernet | Ethernet |
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
首先，這些 FPGA 會充當 NIC，把 LPU 的 C2C protocol 轉成 Ethernet，以連接到以 Spectrum-X 為基礎的 Ethernet scale-out fabric。
V2 Semantic Frame Draft
{
"frame_type": "NARY_RELATION",
"participants": [
{
"node": {
"id": "04_knowledge_base/FPGA",
"label": "FPGA"
},
"role": "fabric_expansion_logic"
},
{
"node": {
"id": "04_knowledge_base/NIC",
"label": "NIC"
},
"role": "network_interface_role"
},
{
"node": {
"id": "04_knowledge_base/Groq LPU",
"label": "LPU"
},
"role": "source_device"
},
{
"node": {
"id": "04_knowledge_base/Chip-to-Chip Interconnect",
"label": "C2C"
},
"role": "source_protocol"
},
{
"node": {
"id": "04_knowledge_base/Ethernet",
"label": "Ethernet"
},
"role": "destination_protocol"
}
],
"qualifiers": {
"condition_text": "Spectrum-X 在此 claim 沒有 canonical mapping；FPGA 主詞由緊鄰前文的 Fabric Expansion Logic 指涉解析",
"numeric_mentions": [],
"temporal_mentions": []
},
"relation_type": "CONVERTS_C2C_TO_ETHERNET_FOR_SCALEOUT"
}V2 Revision Metadata Draft
{
"epistemic_mode": "ASSERTED",
"mapping_status": "PARTIAL"
}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。