The Silicon Sovereign State: Deconstructing the 2025 Cloud CPU Hierarchy

Note: If you buy something from our links, we might earn a commission. See our disclosure statement.

The era of homogeneous merchant silicon is effectively over. As the “Cloud Tax” of virtualization, networking, and encryption threatens to consume up to 35% of available CPU cycles, the major hyperscalers have declared independence by forging their own custom silicon. This research matrix analyzes the four protagonists defining this new paradigm: AWS Graviton4, Google Axion, Azure Cobalt 200, and the high-density merchant challenger, AmpereOne.

We move beyond simple IPC (Instructions Per Clock) marketing claims to dissect the complete SoC architecture. From the divergence between Neoverse V2 and V3 cores to the critical “Uncore” components—such as AWS Nitro and Google Titanium offload systems—we evaluate which architecture truly eliminates latency. Whether you are optimizing for raw single-threaded performance in Azure SQL or seeking maximum container density with AmpereOne, this “Silicon Sovereign State” deep dive reveals the technical and economic reality of the modern ARM datacenter.

Silicon Sovereign State: ARM Processor Comparison

Architecture Analysis 2025

The Silicon
Sovereign State.

The era of homogeneous merchant silicon is over. We analyze the four protagonists defining the new cloud paradigm: AWS Graviton4, Google Axion, Azure Cobalt 200, and AmpereOne.

UPDATED OCT 2025

Vertical Integration vs. Merchant Density.

Scroll to Compare

The Spec Matrix

Direct technical comparison of the leading Arm-based cloud processors. Filter by vendor type to see strategic divergences.

Feature	AWS Graviton4	Google Axion (C4A)	Azure Cobalt 200	AmpereOne M
Core Architecture	Neoverse V2	Neoverse V2	Neoverse V3	Custom (Siryn)
Max Core Count	96	72	132	192
L2 Cache / Core	2 MB	2 MB	3 MB	2 MB
Shared Cache (L3/SLC)	36 MB	80 MB	192 MB	64 MB
ISA	Armv9.0-A	Armv9.0-A	Armv9.2-A	Armv8.6+
Vector Support	SVE2 (4x128b)	SVE2 (4x128b)	SVE2 (Enhanced)	Neon Only
Specialized Offload	Nitro System	Titanium	On-Die Accelerators	None

Synthetic Benchmarks

The Numbers Game

Raw IPC (Instructions Per Clock) tells only half the story. We normalize performance based on cloud vCPU allocation. Cobalt 200 leads in single-threaded database tasks due to cache size, while Graviton4 maintains the edge in cryptography. AmpereOne wins on pure volumetric throughput per rack unit.

Key Insight

“Noisy Neighbor” impact is lowest on AmpereOne due to the lack of SMT (Simultaneous Multithreading), offering the most predictable p99 latency.

Integer Throughput (SPECint rate estimate) Normalized

Graviton4

Cobalt 200

Axion C4A

AmpereOne

Memory Bandwidth Efficiency GB/s per Core

Graviton4

Cobalt 200

Axion C4A

AmpereOne

The Uncore & Software Stack

The CPU core is only one component. Memory controllers, IO lanes, and OS support define the production readiness of these platforms.

Memory Architecture

DDR5 Channels 12 (Graviton4)
Encryption Always On (Hyperscalers)
Tiering CXL 2.0 Ready

Software Readiness

All four chips rely on the ARM64 (Aarch64) ecosystem.

Primary OS Amazon Linux 2023, Azure Linux, COS

Compiler Flags -mcpu=neoverse-v2 / -mcpu=ampere1

Workload Mapping

Redis/Memcached: Cobalt 200
Video Encoding: Axion N4A
Web Serving: AmpereOne
General Purpose: Graviton4

Zero Trust Silicon

Fortress Architecture

How each vendor physically isolates your data. The shift from software-based hypervisors to hardware-offloaded security allows for smaller attack surfaces.

Nitro System

The gold standard. Networking, storage, and security management are physically separated onto the Nitro card. The main CPU sees no hypervisor.

Key Feature

Nitro Enclaves

Titanium

Axion relies on the Titanium offload system for secure boot and root-of-trust validation, ensuring the firmware layer remains uncompromised.

Key Feature

Shielded VMs

Cerberus

Cobalt 200 integrates a Hardware Security Module (HSM) directly on the SoC. Project Cerberus acts as a hardware root of trust for the entire motherboard.

Key Feature

Integrated HSM

Standard ARM

Relies on standard Arm TrustZone and the specific motherboard vendor’s BMC implementation. Less vertical integration than the hyperscalers.

Key Feature

SBSa Compliance

The Economics of
Vertical Integration

Hyperscalers design chips to eliminate margin stacking. By removing the Intel/AMD profit margin, they can offer instances at a 20% discount while improving their own profitability.

1

Spot Availability

Custom silicon (Graviton/Cobalt) often has lower Spot Instance availability than x86, as hyperscalers prioritize reserved capacity for internal services.
2

Licensing Implications

Oracle/SQL Server licensing is often core-bound. The high core count of AmpereOne (192) can actually be a liability for licensed software costs compared to Graviton4.

TCO Simulation (Web Tier)

Legacy x86 (Baseline) 100% Cost

Graviton4 / Cobalt 78% Cost

AmpereOne (Bare Metal) 65% Cost

*Assumes high utilization density on bare metal providers like Hetzner/Oracle.

Visualizing the Gap

Comparing density and memory architecture across the four contenders.

Core Density (Per Socket)

AmpereOne leads in raw density, prioritizing thread count over single-thread complexity.

Shared Cache Size (MB)

Azure Cobalt 200 dominates cache size to mask latency for data-heavy control plane tasks.

Architectural Deep Dive

AWS Graviton4

INCUMBENT

The general-purpose workhorse. By offloading virtualization to the discrete Nitro card, AWS keeps the Neoverse V2 cores focused on compute.

96 Cores (Neoverse V2)
12-Channel DDR5 Bandwidth
Nitro Enclaves for Security

Best For:

Enterprise DBs, HPC, CPU Inference

Google Axion

BIFURCATED

Google splits the line: C4A (Performance) uses Neoverse V2 for heavy lifting, while N4A (Efficiency) uses Neoverse N3 for scale-out microservices.

72 Cores (C4A)
Titanium Offload System
Android Ecosystem Synergy

Best For:

Media Transcoding, Web Front-ends (N4A)

Azure Cobalt 200

INTEGRATED

Microsoft integrates “tax” accelerators directly onto the die. Massive caches and per-core DVFS target the specific inefficiencies of the Azure control plane.

132 Cores (Neoverse V3)
On-die Crypto/Data Accelerators
3MB L2 Cache Per Core

Best For:

Azure SQL, .NET Stacks, Data Processing

AmpereOne

MERCHANT

The density king. No SMT and a custom core design allow 192 physical cores per socket. It prioritizes predictable latency over vector performance.

192 Custom Cores
No Noisy Neighbors (No SMT)
Consistent Frequency

Best For:

Scale-out Containers, Bare Metal Cloud

Q&A

EXPERT INSIGHTS

Which chip is best for AI Inference?

Verdict: Graviton4, Axion C4A, or Cobalt 200.

You strictly need Armv9 and SVE2 (Scalable Vector Extension 2) for efficient CPU-based inference (e.g., Llama.cpp). AmpereOne lacks SVE2 and relies on older Neon instructions, making it significantly slower for matrix math.

Why does Cobalt 200 have such a large cache?

Verdict: To kill latency.

Microsoft’s telemetry showed significant time lost in “cloud taxes” like data movement. The massive 192MB L3 and 3MB L2 cache keep data close to the core, masking the latency of the interconnect and main memory, which is critical for Azure SQL databases.

Is AmpereOne relevant against Hyperscalers?

Verdict: Yes, for density.

Ampere targets the “arms dealer” model. For clouds like Oracle or Hetzner that can’t build their own chips, AmpereOne offers 192 cores per socket. This allows them to sell more vCPUs per rack than they could with off-the-shelf x86 parts, optimizing economics.

What is the “Cloud Tax”?

Verdict: 20-35% of CPU Cycles.

It’s the overhead of virtualization, networking (OVS), and encryption. AWS and Google solve this with offload cards (Nitro, Titanium). Microsoft solves it by putting accelerators on the Cobalt die itself. Ampere solves it by having so many cores that the tax is diluted.

Affiliate Disclosure: Faceofit.com is a participant in the Amazon Services LLC Associates Program. As an Amazon Associate we earn from qualifying purchases.