Arduino Portenta C33 vs ESP32-C6: RA6M5 vs RISC-V, Wi-Fi 6, Thread, Zigbee, CAN and Ethernet

The Arduino Portenta C33 and ESP32-C6 are both modern 32-bit platforms for connected embedded systems, but they are built around very different priorities.

Portenta C33 is a complete industrial System-on-Module:

ESP32-C6 is a highly integrated wireless IoT SoC:

The fundamental difference is:

Quick Comparison

Feature	Portenta C33	ESP32-C6
Main CPU	Arm Cortex-M33	32-bit RISC-V
Clock	Up to 200 MHz	Up to 160 MHz
Low-power core	No separate LP application core	RISC-V LP core up to 20 MHz
SRAM	512 KB	512 KB HP + 16 KB LP
Internal Flash	2 MB	External SPI Flash architecture
Extra Flash	16 MB QSPI onboard	Up to 8 MB on current C6-WROOM modules
Wi-Fi	802.11 b/g/n via ESP32-C3	2.4 GHz Wi-Fi 6 802.11ax + b/g/n
Bluetooth	BLE via ESP32-C3	Bluetooth LE 5.3
802.15.4	No	Yes
Thread	No native radio	Thread 1.3
Zigbee	No native radio	Zigbee 3.0
Ethernet	10/100 PHY onboard	No integrated Ethernet MAC/PHY
CAN	CAN0 + CAN1 signals	2 × TWAI controllers
True DAC	2 × 12-bit DAC	No general-purpose DAC
ADC	2 × 8-channel 12-bit ADC	12-bit SAR ADC, up to 7 channels
Security	TrustZone + SCE9 + SE050C2	Secure boot, Flash encryption, crypto engines, eFuses
USB	USB-C High Speed	USB Serial/JTAG
Best fit	Industrial gateways/controllers	Matter, Thread, Zigbee and low-cost wireless nodes

CPU: Cortex-M33 vs RISC-V

Portenta C33 uses the Renesas RA6M5 with an Arm Cortex-M33 running up to 200 MHz. ESP32-C6 uses a 32-bit RISC-V high-performance core running up to 160 MHz.

The C33 has more clock-speed headroom and is designed for substantial real-time applications, industrial protocols, secure gateways and MicroPython workloads.

The C6 instead combines its CPU very tightly with its wireless hardware, which makes it particularly efficient for compact IoT products.

ESP32-C6 Also Has a Low-Power RISC-V Core

C6 includes a separate:

with low-power memory and peripherals.

This can handle simple wake logic, sensor monitoring and low-power state machines while the main processing domain sleeps.

RAM Is Surprisingly Close

Portenta C33 provides:

while ESP32-C6 provides:

So the headline RAM capacity is similar, although the architectures and memory maps are very different.

Flash and Storage Favour Portenta C33

C33 includes:

as standard.

ESP32-C6 uses external SPI Flash, and current ESP32-C6-WROOM module configurations provide up to approximately 8 MB depending on the module variant.

C33 therefore offers more integrated non-volatile storage for:

• large applications;
• filesystems;
• OTA images;
• web assets;
• logs;
• MicroPython files.

Wireless Is the ESP32-C6 Strength

Portenta C33 uses a separate:

for 2.4 GHz 802.11 b/g/n Wi-Fi and Bluetooth Low Energy.

ESP32-C6 integrates:

directly into the main SoC.

ESP32-C6 Supports Wi-Fi 6

C6 implements 2.4 GHz:

with features such as:

• OFDMA;
• Target Wake Time;
• spatial reuse;
• downlink MU-MIMO support;
• beamformee operation;
• DCM for improved link robustness.

It remains backward compatible with 802.11 b/g/n networks.

Portenta C33 Uses Conventional Wi-Fi 4

C33’s ESP32-C3 provides 802.11 b/g/n Wi-Fi, which is entirely adequate for MQTT, HTTPS, Arduino Cloud, dashboards and remote maintenance.

It does not, however, provide the Wi-Fi 6 features available on C6.

Bluetooth LE 5.3

ESP32-C6 is certified for Bluetooth LE 5.3 and supports features including Bluetooth Mesh, extended advertising, multiple advertising sets and LE power control.

C33’s ESP32-C3 also provides BLE, but the C6 radio subsystem is newer and more capable.

802.15.4 Is the Biggest Connectivity Difference

ESP32-C6 includes:

which enables:

Portenta C33 Has No Native 802.15.4 Radio

The ESP32-C3 used as the C33 wireless processor supports Wi-Fi and BLE but not IEEE 802.15.4.

Native:

• Thread;
• Zigbee;
• Matter-over-Thread;

therefore requires additional radio hardware on a C33 design.

ESP32-C6 Is a Natural Matter Platform

The combination of:

makes ESP32-C6 particularly suitable for:

• Matter devices;
• Thread sensors;
• Zigbee products;
• smart-home switches;
• connected lighting;
• low-power actuators.

Portenta C33 Is More Natural as an Industrial Gateway

C33 combines:

on a production-oriented module.

That suits:

• industrial gateways;
• machine controllers;
• building automation;
• fleet devices;
• process monitoring.

Ethernet Strongly Favours Portenta C33

C33 includes a:

onboard.

The high-density connectors expose the Ethernet signals so a carrier can add the RJ45 connector, magnetics and protection.

ESP32-C6 Has No Integrated Ethernet MAC

Ethernet on C6 normally requires an external solution such as an SPI Ethernet controller or another networking device.

For a combined Ethernet/Wi-Fi/CAN gateway, C33 is therefore much more convenient.

CAN: Both Platforms Support Two Controllers

Portenta C33 exposes:

through its high-density connector.

ESP32-C6 contains:

compatible with classical CAN signalling.

External CAN Transceivers Are Still Required

On both platforms, the controller-side signals are not CANH/CANL.

Each physical CAN network still needs a suitable transceiver.

DAC Strongly Favours Portenta C33

The RA6M5 provides:

and C33 exposes them as:

ESP32-C6 Has No General-Purpose DAC

C6 includes a 12-bit ADC, temperature sensor and PWM hardware, but no normal true analogue-output DAC.

Use PWM plus filtering or an external I2C/SPI DAC if a genuine analogue voltage is needed.

ADC

Portenta C33 includes:

while ESP32-C6 provides:

The exact number of C6 channels exposed depends on the package/module/board.

USB Is Different

Portenta C33 provides a complete:

board interface.

ESP32-C6 contains:

for programming, serial console and debugging.

This should not be confused with a general-purpose high-speed USB host/device controller.

Security Uses Different Architectures

Portenta C33 combines:

for secure execution, hardware crypto and protected credentials.

ESP32-C6 instead integrates:

• secure boot;
• Flash encryption;
• permission control;
• AES;
• ECC;
• RSA;
• SHA;
• HMAC;
• digital-signature hardware;
• XTS-AES;
• TRNG;
• eFuses.

Dedicated Secure Element Advantage

The SE050C2 gives C33 a separate hardware location for long-lived private keys and certificates rather than keeping all sensitive material inside the main MCU.

This can be valuable in industrial identity, PKI and secure manufacturing workflows.

Power and Deep Sleep

Espressif specifies approximately:

for ESP32-C6 deep sleep at SoC level under documented conditions.

Real development-board current will be higher depending on regulator, Flash, LEDs and USB circuitry.

Wi-Fi 6 Target Wake Time

C6 supports:

which can reduce unnecessary radio wake time on compatible Wi-Fi networks.

Portenta C33 Also Targets Low-Power IoT

C33 supports single-cell Li-Po operation through its integrated power-management design.

For real battery-life comparisons, however, always compare complete board current rather than SoC-only figures.

Portenta C33 Is a Complete Production Module

C33 already integrates:

• RA6M5;
• 16 MB QSPI;
• Wi-Fi/BLE radio module;
• Ethernet PHY;
• secure element;
• USB-C;
• power management;
• high-density connectors;
• castellated production mounting.

ESP32-C6 Can Be Used at Different Integration Levels

A C6 design can use:

This gives greater control over cost, size, antenna, Flash, power and exposed I/O.

Software Ecosystems

Portenta C33 has official Arduino support plus MicroPython and the wider Portenta carrier ecosystem.

ESP32-C6 is supported by:

making it particularly strong for connected-device development.

Which Is Better for Matter?

ESP32-C6 because its integrated Wi-Fi/BLE/802.15.4 radio set is designed for modern Matter devices.

Which Is Better for Zigbee?

ESP32-C6 because Zigbee 3.0 runs over its integrated 802.15.4 radio.

Which Is Better for Ethernet + CAN?

Portenta C33 because it already combines:

on one module.

Which Is Better for a Tiny Wireless Sensor?

ESP32-C6 is usually more natural because MCU, Wi-Fi, BLE and 802.15.4 are all integrated in one SoC.

Which Is Better for Analogue Control?

Portenta C33 because it includes two true 12-bit DAC outputs.

Which Is Better for Lowest BOM Cost?

ESP32-C6 is easier to optimise for cost because the processor and all three major wireless technologies are integrated into one chip.

Portenta C33 deliberately integrates more hardware and solves a broader industrial problem.

Decision Table

Requirement	Better fit
200 MHz application MCU	Portenta C33
16 MB onboard QSPI Flash	Portenta C33
10/100 Ethernet PHY	Portenta C33
Dual true DAC	Portenta C33
Dedicated secure element	Portenta C33
Portenta carrier ecosystem	Portenta C33
Industrial production SoM	Portenta C33
Wi-Fi 6	ESP32-C6
Bluetooth LE 5.3	ESP32-C6
Thread	ESP32-C6
Zigbee	ESP32-C6
Matter-over-Thread	ESP32-C6
Integrated low-power core	ESP32-C6
Compact low-cost wireless node	ESP32-C6
Two CAN controllers	Both

Quick Reference

Final Thoughts

Portenta C33 and ESP32-C6 are both excellent connected embedded platforms, but they occupy different parts of the market.

Choose Portenta C33 when the design needs:

• Ethernet;
• industrial buses;
• true analogue outputs;
• large onboard Flash;
• dedicated secure element;
• carrier-board integration;
• a production-ready SoM architecture.

Choose ESP32-C6 when the design needs:

• Wi-Fi 6;
• Bluetooth LE 5.3;
• Thread;
• Zigbee;
• Matter-over-Thread;
• compact hardware;
• low BOM cost;
• low-power wireless operation.

The architectural contrast is simple:

For an industrial gateway, controller or secure Ethernet/CAN product, Portenta C33 is the more complete module.

For a modern smart-home node, Matter device, Thread sensor or Zigbee product, ESP32-C6 has the more appropriate radio architecture.

For detailed C33 wiring, see our Arduino Portenta C33 pinout guide. For the related Arduino 802.15.4 platform, see our Arduino Nano Matter vs ESP32-C6 comparison.