- Apple: fully custom ARM cores (best-known example)
- Google: partially custom (now moving toward more in-house CPU design)
- Amazon: mostly uses ARM cores, but heavily customizes system + now adding its own CPU IP
- Microsoft: historically used ARM cores; recently started building custom silicon, but CPU cores are still largely ARM-based
Let’s break it down precisely
1) Apple (baseline for comparison)
- Uses ARM ISA license
- Designs fully custom CPU cores
- Example: Firestorm, Avalanche (M-series)
This is the gold standard of custom ARM design
2) Google (Pixel / Tensor chips)
Older approach (Tensor G1–G3)
- Used ARM Cortex cores (e.g., Cortex-X1, A78, etc.)
- Focused customization on:
- AI/TPU
- ISP (image processing)
- System-level tuning
CPU cores themselves = not custom
New direction (important shift)
Recent reports indicate:
- Google is working on fully custom ARM CPU cores
- Likely starting in future Tensor generations
Moving closer to Apple-style vertical integration
3) Amazon (Graviton chips)
Current reality
- Chips like AWS Graviton3 use:
- ARM Neoverse cores (server-class Cortex equivalent)
But Amazon:
- Deeply customizes
- Cache hierarchy
- Interconnect
- Memory subsystem
- Power tuning
So:
- CPU core = ARM-designed
- System = heavily Amazon-optimized
Future trend
Amazon is increasingly:
- Adding more in-house silicon IP
- Potentially moving toward custom cores (but not fully public yet)
4) Microsoft (Surface / Azure)
Consumer side (Surface)
- Uses Qualcomm chips like:
- Snapdragon (ARM Cortex-based or semi-custom)
Microsoft itself does NOT design CPU cores here
Cloud side (Azure)
- Has its own ARM chip:
- Azure Cobalt 100
Based on:
- ARM Neoverse cores
Similar to Amazon:
- Not custom cores
- But custom SoC integration
Emerging direction
Microsoft is investing in:
- Custom silicon (AI + CPU roadmap)
But:
- Still behind Apple in CPU core design maturity
5) Big picture comparison
| Company | Custom CPU core? | Approach |
|---|---|---|
| Apple | Yes | Fully custom microarchitecture |
| ? Partial → moving to full | Historically Cortex, now building custom | |
| Amazon | (core) / (system) | Uses ARM cores, custom SoC |
| Microsoft | (core) / (system) | Similar to Amazon |
6) Key insight (this is the real story)
There are three levels of “custom ARM”:
Level 1 — Use ARM cores (most companies)
- Microsoft, Amazon (today), older Google
- Fast to market
- Lower R&D cost
Level 2 — Semi-custom / tuned cores
- Qualcomm (Kryo)
- Google (Tensor early gen)
Level 3 — Fully custom cores (hardest)
- Apple (leader)
- Google (moving here)
- Possibly Amazon/Microsoft in future
Final takeaway
- Only Apple currently does fully custom ARM CPU cores at scale
- Amazon & Microsoft: strong in system-level silicon, not CPU cores (yet)
- Google: transitioning toward Apple’s model
