CM4

Compute Module 4 (CM4) is a compute module developed by the Raspberry Pi Foundation for embedded and industrial applications. It is a modular counterpart to the Raspberry Pi 4 and is designed to be plugged into a carrier board rather than used as a standalone single-board computer. The CM4 exposes the Raspberry Pi 4 hardware interface through a 200-pin connector, enabling integration into custom hardware and systems.

The CM4 uses the Broadcom BCM2711 system-on-chip, a 64-bit quad-core Cortex-A72 CPU running at up to 1.5 GHz. RAM configurations include 1 GB, 2 GB, 4 GB, or 8 GB of LPDDR4 memory. Onboard eMMC storage is available on select variants, and a no-eMMC option is offered for systems that rely on external storage. The module provides a PCI Express Gen 2 x1 lane for attachable devices on carrier boards, enabling options such as storage controllers or other peripherals. I/O such as USB, Ethernet, and display interfaces are provided by the carrier board design.

In terms of form and variants, the CM4 measures about 55 by 40 mm and requires a carrier board to supply most I/O and power. There are standard and Industrial variants, with the Industrial version supporting extended operating temperatures (for example, a broader temperature range) and optional conformal coating for harsher environments.

Software support for the CM4 aligns with the broader Raspberry Pi ecosystem. It runs Raspberry Pi OS and other ARM Linux distributions, and benefits from the same development tools, software libraries, and community resources as other Raspberry Pi devices. Carrier boards, including the official Compute Module 4 IO Board and numerous third-party designs, enable diverse embedded applications.