The Walnut Pi CM2 packs an eight-core Allwinner T527 processor, a 2 TOPS NPU, and WiFi 6 into the same 5.5 x 4.0 cm (2.2 x 1.6 in) footprint as the Raspberry Pi Compute Module 5, making it the first T527-based module to adopt that form factor. The T527's octa-core Cortex-A55 cluster (four cores at 1.8 GHz, four at 1.42 GHz) sits alongside a Mali-G57 MC1 GPU with Vulkan 1.3 support and a secondary E906 RISC-V core clocked at 200 MHz, giving embedded developers an additional low-power coprocessor to work with. Configurations range from 1 GB to 4 GB of LPDDR4 RAM with optional 16 GB eMMC (expandable via resistor selection up to 128 GB), and every SKU includes 8 MB of SPI NOR flash and an on-module Gigabit Ethernet PHY.
Mainline Linux kernel support for the T527's sun55iw3 die family landed in kernel 6.15 with basic SoC bring-up, and community work on top of 6.18 is adding HDMI output, Mali-G57 GPU, and Ethernet drivers. Out of the box, Walnut Pi ships a Debian 12-based Walnut Pi OS alongside Ubuntu, Android, and Home Assistant images, all documented on the project's wiki. The BSP kernel covers what mainline does not yet, so buyers can start building immediately while upstream support matures.
Compatibility with existing CM5 carrier boards comes with caveats. The module exposes its I/O through two 100-pin board-to-board connectors that match the CM5 pinout only partially: it provides a single HDMI 2.0 output instead of two, its MIPI CSI and DSI interfaces are not pin-compatible with Raspberry Pi cameras and displays, and PCIe Gen 2.1 x1 is multiplexed with USB 3.0. Walnut Pi's own CM2 IO board sidesteps these limitations with a full-size HDMI port, an M.2 Key-M slot for NVMe SSDs, a color-coded 40-pin GPIO header, USB 3.0 and 2.0 Type-A ports, and Gigabit Ethernet.
The CM2 starts at $28 (€26) for the 1 GB model without wireless or eMMC, rising to $49 (€45) for the 2 GB variant with 16 GB eMMC and WiFi 6. That compares to $97 (€90) for the equivalent Raspberry Pi CM5. Bundles pairing the CM2 with the IO board run $38 (€35) to $59 (€54), with an optional enclosure adding $8 (€7).
