1. The current stack (why it’s constrained)
Components
-
HBM (High Bandwidth Memory)
• Extremely fast, very close to the GPU
• Expensive, supply-constrained, thermally dense -
CoWoS (TSMC advanced packaging)
• Required to mount HBM next to GPU
• Bottleneck: cost, yield, capacity -
CUDA GPU architecture
• Optimized for training + flexible workloads
• Inference efficiency is good, but not maximal
Result
✅ Amazing for training
❌ Overkill + expensive for large-scale inference
❌ Memory bandwidth ≠ utilization for token streaming
2. Groq’s LPU philosophy (why it’s different)
Key ideas
-
Deterministic execution
• No cache misses
• No dynamic scheduling -
Compiler-defined dataflow
• Memory access is planned, not guessed -
Inference-only focus
• Tokens flow like packets through a network
What this avoids
-
No HBM requirement
-
No CoWoS dependency
-
No massive cache hierarchies
👉 Performance comes from predictability, not brute force bandwidth
3. Where NVLink fits perfectly
NVLink strengths
-
Ultra-high bandwidth chip-to-chip interconnect
-
Low latency, memory-semantic links
-
Scales across:
• dies
• packages
• boards
• racks
The key insight
If inference is streaming, memory can be distributed.
Instead of:
[GPU + HBM] → [GPU + HBM] → [GPU + HBM]
You get:
[LPU] ⇄ NVLink ⇄ [LPU] ⇄ NVLink ⇄ [LPU]
Each chip:
-
Owns a slice of weights
-
Streams activations forward
-
Never needs full model state locally
4. The “bypass CoWoS + HBM” architecture
Hypothetical combined stack
┌───────────────┐
│ LPU Die │ ← Groq-style deterministic core
│ (SRAM-heavy) │
└──────┬────────┘
│ NVLink
┌──────▼────────┐
│ LPU Die │
└──────┬────────┘
│ NVLink
┌──────▼────────┐
│ LPU Die │
└───────────────┘
Why this works
-
Inference = sequential token flow
-
Weights = static
-
NVLink = model-scale fabric
-
SRAM + streaming > HBM + caching
This turns the model into the system, not the chip.
5. Why this makes sense for Nvidia specifically
Nvidia gains
-
Escapes HBM supply + CoWoS bottleneck
-
Adds a pure inference SKU
-
Keeps NVLink as the moat
-
Complements CUDA (training) instead of replacing it
Groq-style IP contributes
-
Compiler-driven scheduling
-
Deterministic latency (huge for real-time AI)
-
Power efficiency at scale
Strategic symmetry
| Training | Inference |
|---|---|
| CUDA GPU | LPU |
| HBM | Distributed SRAM |
| CoWoS | NVLink fabric |
| Throughput | Latency + efficiency |
6. Bottom line
You’re not wrong to say:
“This actually makes a ton of sense.”
Architecturally:
-
Training wants flexibility + brute force
-
Inference wants determinism + streaming
-
NVLink is already the missing glue
-
HBM is the wrong tool for token pipelines
Great — let’s make this concrete and visual by walking through a step-by-step token flow in an NVLink-connected, Groq-style inference system, and then contrast it with today’s GPU+HBM approach.
1. First: the mental picture (what “streaming inference” really means)
Key property of LLM inference
-
Tokens are generated one at a time
-
Each token:
-
Passes through every layer
-
Uses fixed weights
-
Produces one output vector
-
This is not a big parallel matrix problem like training.
It’s a pipeline problem.
2. Traditional GPU inference (why HBM is overkill)
What happens today (simplified)
For every token:
-
Load weights from HBM
-
Move activations through caches
-
Synchronize warps
-
Stall on cache misses
-
Repeat for next layer
Consequences
-
🔥 Massive bandwidth use
-
⏳ Unpredictable latency
-
💸 Expensive silicon (HBM + CoWoS)
-
😬 GPU is solving problems inference doesn’t have
GPUs assume:
“You might need anything, anytime.”
Inference reality:
“I know exactly what I need and when.”
3. Groq-style LPU token flow (deterministic pipeline)
Step-by-step (single chip)
-
Token embedding enters
-
Layer 1 compute starts immediately
-
Output streams directly into Layer 2
-
No cache lookup
-
No dynamic scheduling
-
No stalls
Think of it like:
-
An assembly line
-
Not a warehouse with forklifts
Latency becomes:
latency ≈ number_of_layers × fixed_cycle_cost
Predictable. Boring. Fast.
4. Now add NVLink: model-scale pipelining
Split the model across chips
Example: 96-layer model, 6 chips
| Chip | Layers |
|---|---|
| LPU 1 | 1–16 |
| LPU 2 | 17–32 |
| LPU 3 | 33–48 |
| LPU 4 | 49–64 |
| LPU 5 | 65–80 |
| LPU 6 | 81–96 |
Token journey
Token t
↓
[LPU 1] → NVLink → [LPU 2] → NVLink → ... → [LPU 6]
↓
Output token
While:
-
LPU 2 processes token t
-
LPU 1 already processes token t+1
➡️ Full pipeline utilization
5. Why NVLink is the secret weapon
NVLink advantages here
-
Memory-semantic (not packet guessing)
-
Deterministic latency
-
Orders of magnitude faster than PCIe
-
Designed for tight synchronization
This lets Nvidia:
-
Treat multiple chips as one logical inference engine
-
Without HBM coherence nightmares
-
Without giant monolithic dies
6. SRAM + streaming beats HBM + caching (for inference)
Why SRAM is enough
-
Weights are:
-
Static
-
Reused
-
Predictable
-
-
Access patterns are known at compile time
So:
-
Keep hot weights in SRAM
-
Stream cold weights once
-
Never “hunt” for data
HBM is amazing when:
-
Access is random
-
Working set is huge
-
Compute is chaotic
Inference is none of those.
7. Why this scares everyone (and excites Nvidia)
Hyperscalers
-
Lose differentiation if inference becomes “plug-and-play”
-
GPU margins shrink at scale
Nvidia upside
-
Owns:
-
NVLink
-
Compiler stack
-
Ecosystem
-
-
Can sell:
-
GPUs for training
-
LPUs for inference
-
One fabric for both
-
Strategic punchline
Training creates intelligence.
Inference delivers intelligence.
Nvidia already owns the road between them.
8. One-sentence takeaway
Inference wants to be a factory line, not a warehouse — and NVLink turns multiple small, deterministic chips into one massive, perfectly synchronized machine.
If you want next:
-
🔍 Where this breaks (very large context windows)
-
⚖️ Comparison vs TPU / Cerebras
-
🔧 What compiler magic is required
-
📈 Why latency SLAs change everything
Just tell me which direction to go.
Here’s a clear, non-hand-wavy map of which hyperscalers are most exposed to an Nvidia-style deterministic inference fabric (GPU for training, LPU-like for inference), why, and what realistic moves they have.
The hyperscalers (ranked by exposure)
1. Google (DeepMind + GCP) — most exposed
Why
-
TPU already is a deterministic, inference-friendly architecture
-
Heavy internal reliance on TPU v4/v5 for cost control
-
NVLink-style external fabric threatens TPU’s differentiation
What Google can do
-
✅ Double down on TPU
-
Push TPU as the inference + training stack
-
Keep it vertically integrated (hardware → compiler → model)
-
-
⚠️ Downside:
-
TPU is not an ecosystem
-
Customers want portability, not lock-in
-
Reality
Google is the only hyperscaler already playing this game — and Nvidia is trying to take it from them.
2. AWS (Amazon) — economically exposed, strategically flexible
Why
-
Largest inference bill by far
-
Massive deployment of Inferentia / Trainium
-
Margins matter more to AWS than prestige silicon
What AWS can do
-
✅ Scale Inferentia hard
-
Improve compiler + model support
-
Compete on price-per-token
-
-
✅ Play vendors against each other
-
Nvidia for premium
-
Inferentia for volume
-
-
❌ Cannot abandon Nvidia entirely (customer demand)
Reality
AWS doesn’t need to win architecturally — it just needs inference to be cheap.
3. Microsoft Azure — strategically trapped
Why
-
OpenAI dependency
-
Public commitment to Nvidia
-
Less internal silicon maturity for inference
What Microsoft can do
-
⚠️ Incremental custom accelerators
-
Late to the party
-
-
⚠️ Lean on Nvidia partnerships
-
❌ Very hard to pivot without breaking OpenAI alignment
Reality
Microsoft is the most locked-in hyperscaler right now.
4. Meta (Facebook) — dangerous wildcard
Why
-
Massive inference workloads (feeds, ads, assistants)
-
Strong internal hardware teams
-
Open-source models = inference at scale
What Meta can do
-
✅ Design internal LPUs
-
Meta already builds custom inference silicon
-
-
✅ Optimize models for streaming inference
-
✅ Undercut everyone on cost
-
❌ Doesn’t sell cloud → no ecosystem leverage
Reality
Meta doesn’t need customers — just efficiency. That makes them dangerous.
5. Apple (honorable mention)
Why
-
Edge inference, not cloud
-
Already uses deterministic accelerators (Neural Engine)
Reality
Apple is proof this architecture works — just not a cloud competitor.
What hyperscalers can actually do (options matrix)
| Option | Who can pull it off | Risk |
|---|---|---|
| Build in-house LPUs | Google, Meta, AWS | Compiler + ecosystem burden |
| Price war on inference | AWS | Margin compression |
| Lock customers in | Customer backlash | |
| Partner deeply with Nvidia | Microsoft | Vendor dependence |
| Open inference standards | Meta (maybe) | Helps competitors too |
Why Nvidia’s move is uniquely threatening
Hyperscalers can build chips.
They cannot easily build ecosystems.
Nvidia already has:
-
NVLink (fabric)
-
CUDA / compiler stack
-
Deployment mindshare
-
Model vendor alignment
If Nvidia adds:
-
Deterministic inference silicon
-
That bypasses HBM and CoWoS
-
While plugging into the same software stack
Then hyperscalers face a brutal choice:
Build everything themselves — or buy a cheaper, better, integrated solution.
The uncomfortable truth for hyperscalers
-
Training is prestige
-
Inference is cost
-
Whoever wins inference wins AI margins
And inference is moving toward:
-
Deterministic
-
Streaming
-
Fabric-scaled
-
Boring (in the best way)
That’s exactly Nvidia’s comfort zone.
One-line takeaway
Hyperscalers can build chips, but Nvidia is building the road system — and inference traffic is about to explode.
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