Raspberry Pi Compute Module 4 Review: The Production-Ready CM4 Built for Embedded Products
by Gaurav Sarraf
The Raspberry Pi 4 Model B is one of the most widely used single-board computers in the world. The Compute Module 4 takes the same BCM2711 processor, the same software ecosystem, and the same performance, and packages it into a compact 55 x 40 mm module designed to be embedded inside products rather than used as a standalone board.
At Think Robotics, the Compute Module 4 ranked eleventh by revenue in the last 90 days and thirty-third by order count, making it a consistently purchased product by engineers and developers building custom hardware. This review covers the full range of variants, the key hardware changes from earlier Compute Modules, what the CM4 is designed for, how to get started, pricing in India, and a clear comparison with alternatives.
Module, not board: The CM4 ships without USB ports, HDMI sockets, a microSD slot, or a power connector. All of those are provided by the carrier board. A carrier board is a required separate purchase. For development, the official CM4 IO Board is the recommended starting point.
What Is the Compute Module 4?
The Compute Module 4 (CM4) is a system-on-module. It connects to the carrier board via two 100-pin high-density perpendicular connectors on its underside. This is a deliberate design choice. By moving all the connectors to the carrier board, engineers can design the exact I/O layout their product needs, mount the module in the most compact way possible, and produce a device that looks and behaves like a purpose-built product rather than a hobbyist SBC with a case around it.
The CM4 replaces the SODIMM edge connector used on earlier Compute Module 3+ boards. This new connector is smaller, supports PCIe Gen 2 signalling, and carries the additional interfaces that the BCM2711 SoC provides over its predecessor. It is not backwards-compatible with CM3+ carrier boards.
The 32 Variants: RAM, Storage, and Wireless
The CM4 is available in 32 distinct configurations. Understanding the three axes of variation is the key to choosing the right one. The correct variant depends entirely on the application and whether a wireless radio, onboard storage, or specific memory ceiling is needed.
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RAM
1 GB2 GB4 GB8 GB
All LPDDR4-3200. 1GB or 2GB is sufficient for most headless IoT applications. 4GB or 8GB for web interfaces, desktop environments, or multi-process workloads.
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eMMC Storage
Lite (none)8 GB16 GB32 GB
Lite variants boot from microSD via the carrier board. eMMC runs at up to 100 MB/s and is preferred for production: more durable and resistant to power-interruption corruption.
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Wireless
With Wi-Fi/BTNo wireless
The wireless module carries modular compliance certification, meaning products built with the CM4 wireless variant do not need to repeat the Wi-Fi/BT radio certification independently. Major cost saving for commercial manufacturers.
Pricing range at Think Robotics: approximately Rs. 3,500 for the CM4 Lite (1GB RAM, no wireless) to Rs. 7,500 to Rs. 8,000 for the 4GB, 32GB eMMC, wireless variant. Find all configurations on the Raspberry Pi Compute Module 4 page.
Key Hardware Specifications
BCM2711 Cortex-A72 @ 1.5 GHz1GB to 8GB LPDDR4-3200PCIe Gen 2 x1Dual HDMI via carrier802.11ac Wi-Fi + BT 5.0 (optional)55 x 40 mm footprintProduction until Jan 2034-40°C to +85°C (extended temp)
-20°C to +85°C standard; -40°C to +85°C extended temp variants
Dimensions
55 mm x 40 mm x 4.7 mm
Production Guarantee
In production until at least January 2034
What the CM4 Enables That the Pi 4 Cannot
The CM4's performance is identical to the Raspberry Pi 4 Model B in terms of CPU, GPU, and RAM. The difference is not in computing power but in how the hardware fits into a product.
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Custom Form Factor
The CM4 fits inside products with extremely limited space. Industrial controllers, routers, digital signage displays, medical devices, and point-of-sale terminals can control the physical size and connector layout of the computer inside.
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Industrial Connectivity
A carrier board can expose CAN bus, RS-485, RS-232, multiple UART channels, and other interfaces the standard Pi 4 does not provide. The CM4's GPIO and SPI buses carry these signals without any additional protocol conversion.
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PCIe Gen 2 Expansion
The CM4 exposes a PCIe Gen 2 x1 interface not accessible on the standard Pi 4 in the same way. Carrier boards use this for NVMe SSDs, Coral AI accelerator cards, cellular modems, or other PCIe peripherals.
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Onboard eMMC Storage
Production products generally avoid microSD cards because of susceptibility to data corruption from power interruptions. The CM4's eMMC is soldered to the module and is more appropriate for devices operating continuously in the field.
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Long-Term Availability Until 2034
The CM4 is guaranteed in production until at least January 2034. This matters considerably for product manufacturers who need consistent supply for multi-year production runs. Consumer Pi boards are eventually discontinued; the CM4's commercial supply commitment directly addresses this.
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Modular Compliance Certification
The wireless CM4's modular certification means products built with it do not need to independently repeat Wi-Fi and Bluetooth radio certification. This saves significant time and cost in the product compliance process for commercial manufacturers.
Getting Started: The IO Board
The CM4 module itself cannot be used without a carrier board. For development and prototyping, the official Raspberry Pi Compute Module 4 IO Board is the standard starting point.
The IO Board exposes two full-size HDMI connectors, Gigabit Ethernet, USB ports, a 40-pin GPIO header, PCIe slot, camera and display connectors, a microSD slot (for Lite variants), and a PoE header. It is an open-source design with schematics and PCB layout files publicly available as a starting point for custom carrier board design.
Think Robotics carries the CM4 IO Board alongside the module itself. The IO Board is recommended for anyone developing software for a CM4-based product before their custom carrier board is ready.
Important for eMMC flashing: Not all third-party carrier boards expose the USB boot mode needed to flash the eMMC on non-Lite CM4 variants. Some Waveshare boards do not support this natively. For eMMC flashing, the official IO Board is the most reliable option. The process uses rpiboot on a host Ubuntu or macOS machine and typically takes 30 to 60 minutes.
Products Built on the CM4 at Think Robotics
Several complete systems available at Think Robotics are built directly on the CM4, giving buyers a production-ready path without custom carrier board design.
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reTerminal DM Industrial HMI
The CM4 powers this 10.1" IP65 industrial panel with RS485, RS232, CAN bus, PoE, dual Ethernet, and Node-RED pre-installed. The most capable CM4-based product available for factory floor and infrastructure deployments.
Compact NAS board with 2x M.2 NVMe slots, dual Gigabit Ethernet, USB 3.2, RS485, CAN, and RTC in a VESA-compatible enclosure. A popular choice for home and small-office network storage builds.
DIN rail-mounted CM4 carrier with RS485, CAN, M.2 4G/5G/LoRa support, dual Ethernet, and RTC. Designed for IoT gateways, 4G routers, data acquisition, and industrial PLC applications.
Think Robotics is an authorized Raspberry Pi reseller in India and stocks a selection of CM4 variants. Full pricing across all 32 variants is available on the Raspberry Pi Compute Module 4 page.
Pricing context: A verified Think Robotics buyer noted that 4GB CM4 pricing felt high relative to a Pi 4B 8GB at Rs. 7,500. This is a fair observation: the CM4 costs more per unit than the standard Pi 4 for equivalent RAM, and the premium reflects the eMMC storage, production guarantee, compliance certifications, and industrial design features rather than raw compute performance.
What Users Are Saying
Feedback from Think Robotics verified buyers, the Raspberry Pi official magazine, Tom's Hardware, and developer community posts reflects the practical experience of building with the CM4.
This I/O board has been optimised for using a CM4 as a NAS with no moving parts. Packaging was really good and I got complimentary priority shipping with Bluedart, delivered in 2 days. The aluminium heat sink case makes for very good heat dissipation. Happy with my purchase from ThinkRobotics.
PositiveVerified buyer, ThinkRobotics NAS CM4 product page
Raspberry Pi's compact Compute Module 4 is a popular choice for embedded applications and is used in numerous commercial devices. With a rugged metal case, heatsink base, and external Wi-Fi antenna, it is designed for industrial settings.
PositiveRaspberry Pi Official Magazine, CM4 Nano review
There are 32 variants ranging from the $25 CM4 Lite with 1GB RAM and no storage or Wi-Fi, to a $90 module with 8GB RAM, Wi-Fi, and 32GB of eMMC. The flexibility provided by such a staggering choice enables projects to be designed for different uses and price points.
PositiveTom's Hardware, CM4 review
I received the order on time and the product worked fine in my OpenCV project. But for a 4GB CM4, the pricing feels high relative to a Raspberry Pi 4B 8GB. The premium seems to be for the eMMC and industrial features rather than pure performance.
At first I bought a Waveshare board, but then discovered it doesn't allow you to put the operating system on the eMMC. So I had to buy the official Raspberry Pi IO Board. The eMMC flashing process also took surprisingly long, over 30 minutes.
Setup NoteDeveloper blog, webtechie.be, Sep 2024
Very quick delivery and happy with every purchase. I recently purchased an enclosure for the Compute Module 4. Very interesting device as a complete compact package for a power-efficient system that stays cool.
The Pi 4 Model B is cheaper, has built-in USB and HDMI ports, and is the right choice for prototyping, learning, and standalone computing tasks. Both use the same BCM2711 processor and run identical software. Developers frequently write and test code on a Pi 4 Model B, then transition to the CM4 for production integration.
Pi 4 to develop, CM4 to ship
CM4 vs
Raspberry Pi 5
The Raspberry Pi 5 is substantially faster (2 to 3x CPU improvement), uses the newer BCM2712, and adds a PCIe interface for NVMe. For new projects where raw performance matters, the Pi 5 is the better starting platform. The CM4 remains relevant for embedded production deployments where its 2034 availability guarantee, established compliance certifications, and broader carrier board ecosystem are priorities. A Compute Module 5 is now available for teams wanting Pi 5 performance in module form.
CM4 for compliance, CM5 for performance
CM4 vs
Jetson Orin Nano Module
The NVIDIA Jetson Orin Nano Module delivers up to 67 TOPS of AI inference with a CUDA-capable GPU. For applications requiring hardware-accelerated AI pipelines, computer vision at speed, or generative AI model inference, the Jetson is the correct choice. For applications primarily about running Linux, web services, industrial protocols, or media playback without heavy AI inference, the CM4 is a mature, cost-effective, well-supported platform. They serve different application classes.
Different application classes
Before You Buy
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Software compatibility with Pi 4 is identical. Code developed and tested on a standard Pi 4 Model B transfers to the CM4 without modification in the vast majority of cases.
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Production guarantee until January 2034. Raspberry Pi Trading commits to a minimum production lifetime, which is essential for commercial product lines with multi-year supply requirements.
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Wireless compliance certification is modular. Products using the wireless CM4 variant do not need independent radio certification for Wi-Fi and Bluetooth, saving significant time and cost.
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Extended temperature variants available from 2025. Samsung-memory CM4 variants operate from -40°C to +85°C for outdoor and harsh industrial deployments where the standard -20°C lower limit is insufficient.
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A carrier board is a mandatory separate purchase. The CM4 module alone cannot be used. Budget for at least the IO Board (Rs. 3,500) before the module is operational.
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Not all carrier boards support eMMC flashing. Some third-party boards do not expose USB boot mode for writing to the eMMC. Verify eMMC flashing support before selecting a carrier board for non-Lite variants.
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Wireless variants need antenna hardware in enclosures. The CM4 includes a PCB antenna but an external antenna kit via the U.FL connector is recommended for metal enclosures or where greater wireless range is needed.
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The IO Board is a development platform, not a production carrier. Custom or application-specific carrier boards are the expected production path. The IO Board is the correct starting point for prototyping and software validation only.
Conclusion
The Production Module for Engineers Embedding Raspberry Pi Into Products
The Raspberry Pi Compute Module 4 is the right module for engineers and product designers who need the Raspberry Pi 4's processing capability in a form factor that can be embedded cleanly inside a finished product. The combination of 32 configuration options, modular wireless compliance certification, onboard eMMC storage, PCIe Gen 2 access, dual HDMI output, and a production guarantee until at least January 2034 gives it a practical advantage over the consumer Pi 4 for commercial deployments.
It is not the right choice for buyers who simply need a general-purpose computer, for AI inference workloads, or for new projects where Pi 5 performance is a better fit. But for product teams building custom hardware around a proven, supported Linux computing platform, the CM4 remains one of the most mature and widely deployed embedded computing modules available. Find it at Think Robotics in multiple configurations, with local warranty coverage and fast delivery across India.
32 variantsPCIe Gen 2Onboard eMMCModular Wi-Fi complianceProduction until Jan 2034-40°C to +85°C (extended)
Frequently Asked Questions
No. The CM4 uses a new connector system with two 100-pin high-density perpendicular connectors, replacing the SODIMM edge connector used by the CM3 and CM3+. This change was needed to support additional interfaces including the second HDMI output and PCIe. Adapter boards exist from third-party manufacturers that allow a CM4 to fit in a CM3+ carrier board, but native compatibility requires a carrier board designed specifically for the CM4.
Lite variants have no onboard eMMC storage. They require a carrier board with a microSD card slot for booting the operating system. Standard variants have 8GB, 16GB, or 32GB of eMMC soldered directly onto the module. For production deployments, eMMC is preferred because it is more durable and less prone to data corruption from power interruptions than microSD. Lite variants are lower cost and suitable for prototyping or applications where external storage is intentionally used.
Yes. The wireless CM4 includes an onboard PCB antenna. For applications inside metal enclosures or where greater wireless range is needed, an optional external antenna can be connected via the U.FL connector on the CM4. The external antenna kit is sold separately. The wireless module's compliance certification covers both the onboard and external antenna configurations.
Yes. The CM4 uses the same BCM2711 SoC as the Raspberry Pi 4 Model B and runs the same operating system images. Software developed and tested on a Pi 4 Model B will transfer directly to the CM4 without modification in the vast majority of cases. This is the recommended development approach: write and validate software on a standard Pi 4, then move to the CM4 for embedded product integration.
Standard CM4 variants operate from -20°C to +85°C, covering most indoor industrial and some outdoor applications. Extended temperature variants released in 2025, using Samsung memory, operate from -40°C to +85°C, which makes them suitable for cold outdoor environments and industrial automation in temperature-varying factory floors. Pricing on extended temperature variants starts at $50 versus $30 for the base standard variant. Contact Think Robotics for current availability of extended temperature CM4 variants for specific project requirements.
Get the Raspberry Pi Compute Module 4 from India's Authorized Reseller
32 variants in stock. Local warranty, competitive pricing, and fast delivery across India. IO Board, carrier boards, and CM4-based complete systems also available.
