The Radxa Dual 2.5G Router HAT adds high-speed networking and NVMe storage expansion to single-board computers like the Raspberry Pi 5 and Radxa ROCK series, using a single PCIe connection in a compact form factor.

The HAT uses the ASM2806 PCIe Gen3 switch chip to convert a single PCIe lane into multiple downstream lanes. This enables simultaneous use of both the dual Ethernet ports and the NVMe SSD slot, addressing the PCIe limitations common in most SBCs.

Radxa Dual 2.5G Router HAT Accessories
(click image to enlarge)

The device features two 2.5 Gigabit Ethernet ports powered by the Realtek RTL8125B controller. This configuration delivers faster and more reliable network performance, which is beneficial for applications such as routing, firewalls, and data-heavy communication between systems.

For storage, an M.2 M Key connector provides support for PCIe Gen3 x1 NVMe SSDs. The slot accepts 2230, 2242, 2260, and 2280 SSD sizes, giving users flexible options for high-capacity, high-speed storage, whether for data or booting the operating system.

Radxa Dual 2.5G Router HAT Installation
(click image to enlarge)

An FPC expansion interface is also included, offering a second PCIe Gen3 x1 lane that can be used to connect additional peripherals or expansion boards. This interface shares PCIe bandwidth with the onboard NVMe slot, which may affect performance when both interfaces are in active use.

Power is supplied through a 12V DC jack with a 5.5 mm outer and 2.5 mm inner diameter. Once connected, the HAT delivers power to the SBC through the 40-pin GPIO header. This setup simplifies wiring by eliminating the need for a separate power supply for the host board.

Compatibility extends to Radxa’s ROCK 2A, 2F, 4D, and 5C, as well as the Raspberry Pi 5. The package includes a flexible FPC adapter cable, mounting hardware, and a heatsink for the PCIe switch chip to ensure stable operation under load.

Radxa Dual 2.5G Router HAT Interfaces
(click image to enlarge)

Setting up the HAT involves enabling PCIe support on the Raspberry Pi 5 via configuration file updates. Users can also enable PCIe Gen3 for increased throughput. NVMe SSDs can be used either for general storage or system boot with EEPROM configuration adjustments.

Standard Linux tools are used for software setup. Ethernet ports typically appear as eth1 and eth2, and the SSD can be formatted and mounted using tools such as lsblk, mkfs, and mount. Full setup and troubleshooting instructions are available on Radxa’s official documentation page.

Further Information

The Radxa Dual 2.5G Router HAT is available from AliExpress for $41.20 and from AraceTech for $40.00.