2025-08-12_scaling-the-memory-wall-the-rise-and-roadmap-of-hbm::HBM25-0032
① SA Source
- Source: 開啟完整 SA 文章
- Section:
Custom Base Die - Line hint:
287
Context Before
More of the area of the base die can be utilized to add in significant functionality with various custom base die configurations. Tying this back to the discussion on the importance of shoreline -** there is a huge amount of untapped shoreline real estate that exists on the HBM base die of today which is going to be unleashed from HBM4 onwards.**
We expect Nvidia and AMD to come out with their custom HBM implementations with HBM4, with other accelerator designers likely to only have a custom base die implementation by HBM4E in the 2027 timeframe.
Evidence
We believe these custom base die implementations will provide 3 main functions: memory controller offload, shoreline expansion, and compute in base die.
Context After
Getting Down to the Wire: Better PHYs
At the heart of the problems with the current base die design is the PHY that interfaces with the host. HBM uses a standard DDR PHY using planar transistors fabricated on a DRAM process. These lower performance transistors hamper the signaling capability of PHY so that signals can only be fixed and unidirectional at slow speeds.
② Atomic Claim
SemiAnalysis 預期 HBM custom base die 的三大功能為 memory-controller offload、shoreline expansion、compute in base die。
- Epistemic Mode:
EXPECTED - Mapping Status:
COMPLETE
③ Semantic Frame
{
"attribute": "main_functions",
"context_nodes": [],
"entity": {
"id": "04_knowledge_base/Custom Base Die",
"label": "Custom Base Die"
},
"frame_type": "ATTRIBUTE",
"qualifiers": {
"condition_text": null,
"numeric_mentions": [
"3"
],
"temporal_mentions": []
},
"value": {
"numeric_mentions": [
"3"
],
"value_text": "memory controller offload; shoreline expansion; compute in base die"
}
}④ Canonical Entity Mapping
| Role | Surface Label | Canonical Target |
|---|---|---|
| entity | Custom Base Die | 04_knowledge_base/Custom Base Die |
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。