Radxa has released specs for a $39 “Rock Pi” Raspberry Pi lookalike board with a Rockchip RK3399, USB 3.0, M.2, HDMI 2.0, and native GbE, plus optional WiFi, BT, and PoE. The Rock Pi runs Linux or Android. It closely matches the RPi 3 layout, just like the RK3399-based NanoPi M4, and it seems it may be the most affordable RK3399 based SBC right now, with a starting price of $39 with 1GB RAM. The Rock Pi Model A sells for $39 (1GB), $49 (2GB) and $65 (4GB) respectively. The Model B, which includes PoE and a WiFi-ac/Bluetooth 5.0 wireless module will sell for $49 (1GB), $59 (2GB) or $75 (4GB). The only real difference between model A and model B is that the latter includes a wireless module, and optional support for PoE. The ports on the 85 x 54mm Rock Pi are placed at the right side, where Pi lovers would expect them to be. Unlike the RPi 3B or 3B+, the GbE port is standard, offering at least 939Mbps. Like the 3B+, it supports Power-over-Ethernet using the same official Raspberry Pi PoE HAT. Thespecs are almost similar to those of the $75 (2GB) NanoPi M4.
The Rock Pi 4 seems to be the most affordable RK3399 SBC yet, even cheaper than the smaller, more limited (1GB only) $50 NanoPi Neo4. It also offers a microSD slot and an empty eMMC socket in addition to the M.2. A key selling point of the RK3399, is the HDMI 2.0 port. The board is equipped with 2-lane MIPI-DSI and -CSI interfaces for dual displays and camera attachments, respectively. Other available features include an audio jack with mic, an RTC, and a USB Type-C port for a wide-range of input power.
