OSM vs. SMARC: Which Form Factor Is Right for Your Design?

Published on April 16, 2026

Choosing a compute module form factor is one of those decisions that feels like an implementation detail early in a project and becomes a structural constraint the moment you commit to a PCB layout. OSM (Open Standard Module) and SMARC (Smart Mobility ARChitecture) are the two dominant standards for surface-mount and board-to-board embedded compute modules in the industrial and IoT space. They target similar applications, share some underlying philosophy, and yet arrive at meaningfully different answers to the same core questions: How small does the module need to be? How complex can the carrier board be? How long will this design live in production?

This piece is written for engineers who have a project in hand — an industrial gateway, a medical edge device, a smart metering concentrator, an HMI — and need a principled basis for choosing between the two. We cover mechanical specifications, signal routing implications, thermal characteristics, operating system support, and long-term supply considerations.

Why the Form Factor Decision Matters More Than It Looks

The instinct to defer the module form factor choice is understandable — the processor, memory, and wireless stack feel like the real decisions, and the mechanical package feels like detail. That instinct is wrong, and it costs teams real money.

A form factor choice locks in your carrier board pinout, your thermal management strategy, your connector type and count, and your vendor qualification path. The SMARC and OSM specifications define not just dimensions but signal assignments, power delivery expectations, and lifecycle commitments from participating vendors. Switching form factors after the first PCB spin means a new carrier board, a new layout, and typically three to six months of schedule.

The other pressure point is regulatory. CE, FCC, and UL certifications are often scoped to a module-plus-carrier-board combination. Ezurio's pre-certified modules are designed so the module carries the bulk of the RF and emissions certification burden, leaving the carrier board in a simplified compliance posture. But that arrangement only works if the form factor and its signal routing are correctly understood from the start. A mismatch between module capabilities and carrier board design — for instance, routing high-speed differential pairs incorrectly because you misread the OSM pin pitch as SMARC-compatible — will surface as a certification failure, not a debug problem.

The Two Standards: What the Specifications Actually Say

SMARC 2.1

SMARC is maintained by the SGET (Standardization Group for Embedded Technologies) and is currently at version 2.1.1, ratified in 2024. The specification defines a module measuring 82 mm × 50 mm (full size) or 82 mm × 30 mm (short size), with a 314-pin edge connector using a 0.5 mm pitch MXM-style interface. It was originally designed with mobile and automotive applications in mind — "Smart Mobility ARChitecture" — which explains its emphasis on display interfaces, camera buses, and power management flexibility.

SMARC 2.1 added standardized support for PCIe Gen 3, extended the USB 3.0 signal definitions, and formalized the MIPI CSI-2 camera interface lanes. The SMARC 2.1.1 addendum "gives designers freedom with regards to SerDes signaling over PCIe for Gb Ethernet, as well as full USB-C support offering USB 3.2 Gen1 and DisplayPort Alt Mode over one single USB interface." The specification is explicitly silicon-agnostic: it supports ARM Cortex-A class processors and x86 designs from any vendor. Signal definitions for HDMI, LVDS, MIPI DSI, and dual Gigabit Ethernet make SMARC a strong fit for any application that needs display output or rich connectivity as a baseline.

Ezurio's SMARC modules leverage chipsets from both NXP (i.MX 91, i.MX93, i.MX 95, i.MX 8M Plus, and i.MX 8M Mini) and MediaTek (Genio 510, Genio 700). Ezurio's roadmap includes an evolving product line as new chipsets become available for our partners, giving our customers an upgrade path for the future.

The MXM connector handles power delivery, high-speed differential signals, and low-speed I/O on the same connector block. This is efficient from a module footprint standpoint but introduces routing complexity on the carrier: the MXM's fine pitch demands controlled impedance on high-speed lanes and careful signal segregation to prevent interference between USB 3.0 and PCIe lanes and adjacent lower-speed signals.

OSM (Open Standard Module)

OSM is the newer standard, also maintained by SGET, with version 1.1 published in 2020 and version 1.1 Rev B in active use. OSM was explicitly designed as the successor form factor for applications where SMARC is physically too large, and it defines three sizes: S (30 mm × 30 mm), M (45 mm × 30 mm), and L (45 mm × 45 mm). The connector is a land grid array (LGA) — the module solders directly to the carrier board at 0.8 mm pitch, like a large BGA component.

The philosophical difference is significant: OSM treats the module as a soldered component, not a replaceable daughterboard. The LGA attachment is permanent in normal assembly. There is no connector to unseat, no mechanical cycling, and no connector insertion force specification to manage. The tradeoff is that field replacement of an OSM module requires rework — reflowing the module off the carrier board — which is straightforward in a manufacturing environment but impractical in the field without specialized equipment.

Ezurio's OSM modules leverage chipsets from both NXP(i.MX 91) and MediaTek (AM62, AM62L, and AM67), with the same plan to continue to expand offerings for a future upgrade path for our customers.

OSM's signal set reflects its embedded-first focus. GPIO, UART, SPI, I2C, and single-channel USB are the baseline I/O types. PCIe is optional and present only on M and L sizes. Display interfaces are limited relative to SMARC. What OSM prioritizes instead is a minimal, clean signal footprint that supports simpler carrier board design — fewer high-speed differential pairs to route, lower layer count requirements, and more forgiving impedance tolerances.

Mechanical and Electrical Comparison

The differences in physical dimensions and attachment method drive most of the downstream design decisions. The table below summarizes the key parameters across the two standards.

Parameter	SMARC 2.1	OSM Size S	OSM Size M	OSM Size L
Module dimensions	82×50 mm (full) 82×30 mm (short)	30×30 mm	45×30 mm	45×45 mm
Connector type	MXM 0.5 mm pitch 314-pin	LGA 0.8 mm pitch	LGA 0.8 mm pitch	LGA 0.8 mm pitch
Attachment method	Board-to-board connector (replaceable)	Soldered LGA (permanent)	Soldered LGA (permanent)	Soldered LGA (permanent)
Carrier PCB layers (typical)	6–10 layers	4 layers	4–6 layers	4–6 layers
Field replaceability	Yes — pluggable	No — rework required	No — rework required	No — rework required
Display interfaces	HDMI, LVDS, MIPI DSI	Limited	Limited	MIPI DSI (optional)
Primary I/O focus	Display, Camera, PCIe, USB 3.0, dual GbE	GPIO, UART, SPI, I2C, USB	+ optional PCIe	+ optional PCIe, display

What That Table Means in Practice - Six Takeaways

Size vs. flexibility: OSM is much smaller and better for space-constrained designs, while SMARC is larger but offers more flexibility.
Connector vs. soldered: SMARC uses a removable connector (easy to swap/upgrade), whereas OSM is soldered down (permanent, lower cost).
Field replaceability: SMARC modules can be replaced in the field; OSM modules require rework and are not intended to be replaced.
Carrier board complexity: SMARC typically needs more PCB layers (higher cost/complexity), while OSM allows simpler, lower-cost carrier designs.
I/O capability: SMARC supports richer, high-speed interfaces (PCIe, multiple displays, networking), while OSM focuses on simpler I/O with limited expansion.
Display support: SMARC has strong built-in display support; OSM has limited or optional display capabilities.

Thermal Considerations

SMARC modules are generally larger and often heavier, which provides a larger thermal spreader area. Many SMARC modules include an integrated heatsink or thermal pad specification as part of their datasheet — they expect the carrier board or enclosure to provide a thermal interface. For industrial applications in sealed enclosures (IP67 or higher), this matters: you need a reliable thermal path from the module to the enclosure wall, and SMARC's larger footprint gives you more surface area to work with.

OSM modules, being smaller, dissipate heat over a smaller footprint. At lower power envelopes — sub-3W typical for IoT applications — this is fine. The LGA attachment itself provides some thermal conductivity through the solder joints into the carrier board ground plane, which acts as a heat spreader. However, for compute-intensive OSM deployments (edge inference, video analytics) where the SoC may approach 5–8W, the thermal path needs to be explicitly designed: carrier board ground plane copper weight, thermal vias under the module, and the enclosure contact interface all need to be specified, not assumed.

Deployment Risk: Do not assume that a small OSM module in a sealed plastic enclosure will self-regulate thermally at high computational loads. OSM Size M and L modules running inference workloads in sealed enclosures without a copper thermal interface to the enclosure wall have shown junction temperatures 20–30°C higher than projected under continuous load. Size the thermal path before finalizing the enclosure design.

Operating System and Software Stack Support

Both form factors support Linux — specifically Yocto-based distributions — and both have active BSP (Board Support Package) ecosystems. The practical difference is in ecosystem maturity and the availability of pre-built BSPs for specific processors.

SMARC has a longer deployment history and a larger vendor base. If you are running an NXP i.MX 8M Plus on SMARC, there is a well-established Yocto layer with maintenance histories measured in years. Industrial Linux distributions like Timesys Factory have formal SMARC support. This matters for medical and defense applications where a documented, qualified software supply chain is a procurement requirement.

OSM is newer and the BSP ecosystem reflects that. Most OSM BSP support is currently Yocto-based and maintained by module vendors. Android and RTOS (FreeRTOS, Zephyr) support exists for specific OSM modules but is less uniformly available across the ecosystem. For pure Linux applications, OSM BSP quality is good and improving. For applications that need an RTOS on the application processor or full Android support, verify BSP availability for your specific module before committing to OSM.

Real-time control applications are a nuanced case. Neither SMARC nor OSM inherently supports hard real-time on the application processor — that is a function of the SoC and RTOS configuration, not the form factor. However, SMARC's richer I/O set enables co-processor architectures where a dedicated microcontroller handles real-time tasks and communicates with the SMARC module over PCIe or a fast serial bus. OSM's simpler I/O set is a better fit for single-processor designs where the application processor handles both compute and control.

Ezurio's extensive software development gives our customers multiple options for OS support, such as Linux, Android, U-Boot, Buildroot, Debian, FreeRTOS, QNX, Yocto, and more. And our partnership with Kynetics brings their Embedded Android Developer Toolkit to our Nitrogen95 SMARC and Tungsten700 SMARC, with more to come in the future.

Where Each Form Factor Belongs: A Decision Framework

The question is not which form factor is "better" — it is which one is right for your specific constraint set. Work through the following in order:

Assess your size envelope first. If your enclosure or PCB area constraint means the system-on-module must fit within 35 mm × 35 mm, SMARC is eliminated regardless of any other factor. OSM Size S is your starting point.
Assess your display requirements. If the product has a primary display — HDMI or LVDS to an industrial panel — SMARC's display interface support is substantially richer. OSM is not the right choice for display-primary applications unless you are adding an external display controller IC on the carrier board, which adds cost and BOM complexity.
Assess field service requirements. If your customers or field service teams need to swap the compute module without specialized rework equipment, SMARC's connector-based attachment is the only choice. Healthcare devices, industrial equipment sold on a module-exchange service contract, and telecom infrastructure all fit this profile.
Assess product lifetime and vendor lock-in risk. SMARC's connector interface means you can swap a module from one vendor for another vendor's module on the same carrier board, provided both comply with the specification — a real hedge against end-of-life and supply disruption. OSM's LGA attachment does not provide the same insurance: the pad layout is standardized, but reflowing a module mid-production-run to switch vendors is a manufacturing change with qualification implications.
Assess wireless requirements. Ezurio's pre-certified wireless modules — covering Bluetooth, Wi-Fi, and cellular — integrate cleanly alongside both form factors. An OSM module handling local edge compute combined with a dedicated Ezurio wireless module handling BLE or LTE-M connectivity is a clean architecture: each module does one job well, with the wireless module pre-certified and the compute module handling data processing. This separation avoids the complexity and certification risk of integrating wireless into a custom carrier board design.

Regulatory and Certification Considerations

Enterprise IoT products sold into regulated markets — industrial (IEC 62443), medical (IEC 62304, FDA pre-market submissions), automotive (ISO 26262) — face a certification burden that the form factor choice directly affects.

SMARC modules with long production histories often carry extensive compliance documentation: RoHS, REACH, and in some cases IEC 61000-4 EMI/EMC pre-qualification. This documentation can significantly simplify a customer's system-level certification process. SGET's SMARC specification is recognized by regulatory consultants as a stable, well-documented standard, which helps when presenting a design to a notified body or working through a technical file for CE marking.

OSM's newer status means the compliance documentation ecosystem is less mature at the ecosystem level. Individual OSM module vendors maintain full RoHS, REACH, and applicable FCC/CE certification for their specific modules. But the concept of "certified OSM module = simplified system certification" is not yet as established in practice as it is for SMARC. Engineers targeting medical or industrial functional safety certification should confirm with their regulatory consultant how the form factor is documented in the technical file before committing.

The EU Cyber Resilience Act (CRA), which came into force in December 2024 with a compliance deadline of December 2027, requires that embedded products with digital elements have documented vulnerability management and software update mechanisms. This is a software obligation, not a hardware one, but it reinforces the importance of choosing a module with a qualified, maintained BSP and a vendor with a published security policy. Verify ongoing software maintenance commitments before selecting any module, regardless of form factor.

You can learn about Ezurio's security efforts for CRA and RED Cyber compliance in our security center.

Conclusion

OSM and SMARC are not interchangeable options for the same application space. SMARC is the right choice when you need display output, field-replaceable compute, or the richest possible I/O set — and you have the carrier board design resources to support it. OSM is the right choice when you are size-constrained, when carrier board simplicity is a priority, and when the application is compute-forward rather than display-forward.

Ezurio's pre-certified wireless modules are designed to complement both form factors without adding RF certification burden to the carrier board. Whether you are building a compact OSM-based sensor node or a SMARC-based industrial gateway, starting with a pre-certified, long-lifecycle wireless module removes one of the most time-consuming variables from the design and certification process.

Learn more about our SMARC and OSM SOMs on our website, or talk to our engineering team about module selection, carrier board design guidance, and pre-certification support: ezurio.com/contact