Radxa CM5 – A Rockchip RK3588S module (somewhat) compatible with Raspberry Pi CM4

Radxa has been working on the ROCK 5 Compute Module (aka Radxa CM5) system-on-module compatible with Raspberry Pi CM4, but based on the more powerful Rockchip RK3588S octa-core Cortex-A76/A55 SoC.

Just like the Raspberry Pi Compute Module 4, it comes in a 55 x 40mm form factor, but instead of just two high-density 100-pin board-to-board connectors, the module includes three to cater for the additional I/Os from the Rockchip processor, just like they did for the Radxa CM3 equipped with a Rockchip RK3566 processor.

Radxa CM5

Radxa CM5 specifications:

  • SoC – Rockchip RK3588S octa-core processor with
    • 4x Cortex‑A76  cores @ up to 2.4GHz, 4x Cortex‑A55 core @ 1.8GHz
    • Arm Mali-G610 MP4 “Odin” GPU
    • Video decoder – 8Kp60 H.265, VP9, AVS2, 8Kp30 H.264 AVC/MVC, 4Kp60 AV1, 1080p60 MPEG-2/-1, VC-1, VP8
    • Video encoder – 8Kp30 H.265/H.264 video encoder
    • 6 TOPS NPU
  • System Memory – 4GB, 8GB, or 16GB LPDDR4x‑4224 SDRAM
  • Storage – Optional 8GB, 16GB, 32GB, 64GB, or 128GB eMMC flash memory up to 250MB/s
  • 3x 100-pin 0.4mm pitch board-to-board connectors
    • Storage
      • 2x SATA interfaces, one shared with USB 3.0, the other with PCIe
      • SD card suppor via SDIO interface
    • Video Interfaces
      • 1x HDMI 2.1 up to 8K60
      • 2x 4‑lane MIPI DSI interfaces (MIPI DSI0, MIPI DSI1)
      • 1x eDP up to 8K60 (shared with HDMI)
    • Camera I/F
      • 2-lane MIPI CSI camera interface
      • 4‑lane MIPI CSI camera interface
    • Networking – Gigabit Ethernet (No PHY on module)
    • USB – 1x USB 2.0, 1x USB 3.1 port (5Gbps), 1x USB 3.0 host port
    • PCIe – 2x PCIe 1‑lane host, Gen 2.1 (5Gbps)
    • Other peripherals
      • 1x SDIO 3.0
      • Up to 50x GPIO supporting either 1.8V or 3.3V
      • Up to 8x UART, 8x I2C, 4x SPI
      • 1x PCM
      • Up to 8x PWM channels
      • 2x ADC
  • Supply Voltage – Single +5V DC input
  • Dimensions – 55 x 40 x 3mm (PCB)

Rockchip RK3588S Raspberry Pi CM4 moduleRadxa CM5 3x 100 pin board to board connectorRadxa CM5 is designed to help people requiring custom carrier boards. It supports the same operating systems as the Rockchip RK3588-powered ROCK 5B single board computer including Ubuntu 20.04, Debian 11, and Android 12, plus Buildroot and the Yocto Project build system are also available.

The SoM can be used for Robotics, HMI, vending machines, Smart Home devices, IoT gateways, industrial controllers, medical equipment (TBC), and so on. It’s compatible with the ROCK3 Compute Module IO board, and should work on most carrier boards designed for the Raspberry Pi Compute Module 4 as well, although there are caveats, as we’ll discuss below.
ROCK3 Compute Module IO board with Radxa CM5

There will be exceptions, as some of the interfaces, such as the second HDMI interface, are missing, and the module is too small / the processor too big, to have enough space for a wireless module, so it would have implemented on the carrier board, or using a USB dongle. The module also lacks the Gigabit Ethernet PHY (such as RTL8211F) found on RPi CM4 and Radxa CM4, so I don’t see how Ethernet can work on existing carrier boards as well. Sadly, that means backward compatibility is limited and only works if you don’t need networking.

Raspberry Pi CM4
Radxa CM3
Radxa CM5
Broadcom BCM2711 quad-core Cortex-A72
processor @ 1.5 GHz with VideoCore VI GPU
Rockchip RK3566 quad-core Cortex-A55
processor @ 2.0 GHz with Arm Mali-G52 2EE GPU,
0.8 TOPS AI accelerator
Rockchip RK3588S octa-core Cortex-A76/A55
processor @ 2.4 GHz / 1.8 GHz with Arm Mali-G610 MP4 GPU,
6 TOPS AI accelerator
System Memory
1GB, 2GB, 4GB or 8GB LPDDR4-3200 SDRAM
4GB, 8GB or 16GB LPDDR4x-4224 SDRAM
None, 8GB, 16GB, 32GB, 64GB, 128GB eMMC Flash memory up to 100MB/s
SDIO 2.0 for CM4Lite only
None, 8GB, 16GB, 32GB, 64GB, 128GB eMMC Flash memory up to 250MB/s
SDIO 3.0
Display interfaces
2x HDMI up to 4Kp60
1x 2-lane MIPI DSI display interface
1x 4-lane MIPI DSI display interface
1x HDMI up to 4K60
2x 4-lane MIPI DSI display interfaces
1x 4-lane LVDS multiplexed with 1x MIPI DSI
1x eDP up to 4Kp60
1x HDMI up to 8Kp60
2x 4-lane MIPI DSI display interfaces
1x eDP up to 8K60
Camera interfaces
1x 2-lane MIPI CSI camera port
1x 4-lane MIPI CSI camera port
Audio codec
No (must be on carrier board)
No (must be on carrier board)
Gigabit Ethernet PHY with IEEE 1588 support
Gigabit Ethernet PHY (RTL8211F)
with optional IEEE 1588 support
Gigabit Ethernet (No PHY)
Optional Wi-Fi 5 & Bluetooth 5.0
1x USB 2.0
1x USB 2.0, 1x USB 3.0 (5 Gbps)
1x USB 2.0, 1x USB C 3.1 port (5Gbps), 1x USB 3.0 host port
1× 1-lane PCIe Gen 2 (5Gbps)
2× 1-lane PCIe Gen 2.1 (5Gbps)
2x SATA multiplexed
with PCIe and USB 3.0 interfaces
28x GPIO
Up to 5x UART
Up to 5x I2C
Up to 5x SPI
1x SDIO interface
1x DPI (Parallel RGB Display)
1x PCM
2x PWM channels
Up to 3x GPCLK outputs
1.8V and 3.3V support
50x GPIO:
Up to 8 × UART
Up to 8 × I2C
Up to 4 × SPI
1x SDIO interface
1x PCM
Up to 8x PWM
2x ADC
1.8V and 3.3V support
Board-to-board connectors
2x 100-pin B2B connectors
3x 100-pin B2B connectors
Supply Voltage
Single 5V input voltage
55 x 40 mm

Besides working on a Rockchip RK3588S module with the Raspberry Pi CM4 form factor, the company is also prepping the Radxa NX5 SO-DIMM module that offers compatibility with NVIDIA Jetson Nano, TX2 NX, and Xavier NX system-on-modules. We’ll cover that one once we have more details.

Radxa guarantees the availability of the Radxa CM5 until at least September 2032, or a 10-year long-term supply commitment. We don’t have pricing information just yet, but I’d expect the Radxa CM5 to cost a bit more than the Radxa CM3 or Raspberry Pi CM4. A few additional details may be found on the wiki.

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ROCK 5 ITX RK3588 mini-ITX motherboard

17 Replies to “Radxa CM5 – A Rockchip RK3588S module (somewhat) compatible with Raspberry Pi CM4”

    1. Turing RK1 is a SO-DIMM module, so it should be more like Radxa NX5.
      It’s supposed to have PCIe Gen 3.0 exposed since RK3588 supports it, but not RK3588S..

  1. If they ditched the Ethernet PHY just because they don’t have enough space on the PCB, they should rather ditch the eMMC memory. Most carrier boards have a usb/sd-card slot anyways

  2. I wish they could find the time to publish a basic mainline device tree for the CM3 before diluting their engineering resources with another product

    1. Care to elaborate on that? How should a board vendor provide a ‘mainline device-tree’ if the process as a whole is broken by design? In the sense of taking years until everything works (if it ever does). You should better know than most that upstreaming an ARM SoC usually takes until the hardware is obsolete.

      Is there something for Rockchip comparable to linux-sunxi’s Status Matrix?

        1. > it is unfortunately pine64 specific.

          Thank you! Reflecting more or less RK356x in general 🙂

          RK3399 is a 2015 design that appeared on consumer hardware in 2016. Rockchip employees started mainlining in Aug 2016 (Armbian’s Chief Advertising Officer still tries to create the impression ‘Armbian’ would’ve done all the work) and when looking at Linux 5.19 changelog 6 years later there are still plenty of RK3399 (device-tree) related fixes.

      1. Not true with Rockchip that work on mainline kernel and Linux 5.19 have already some parts of RK3588 drivers. But could take more time with GPU as ARM doesn’t release their specs and Rockchip probably have NDA, so Panfrost driver authors need to reverse drivers. Maybe the amount of work made on other generation will reduce the needs for this one? RISC-V opensource GPU progress step by step, hope we will see it soon in real (ASIC) hardware, with ARM or RISC-V CPU based SoC, this will greatly simplify the support process. I would really appreciate a good RISC-V Rockchip SoC (they already published two RISC-V MCU +ARM CPU mixed SoC, RV1126 and RV1109) :). Until now the AllWinner D1 is the more efficient with their T-Head (open source) design, but limited to one core at 1GHz accessible to developers, there are T-Head server SoCs, but probably only used by Alibaba. Looks like Starfive one using (closed source) SiFive design is far less efficient, and even with 4 cores @ 1.2GHz, RAM transfers are more than 2 times slower than on D1.

        1. > Not true with Rockchip that work on mainline kernel

          Sure but the whole mainlining process will take years as we can see with RK3399. It happens in small slices and sometimes patchsets need up to 10 revisions which will take months for a simple feature like e.g. USB until stuff gets accepted and becomes part of vanilla mainline kernel.

          As such a board vendor can only provide ‘a basic DT’ if starting to collect the patchsets floating around maintaining themselves. As it’s done for example by Hardkernel’s Dongjin (tobetter) or Oleg (balbes150) with his media kernel.

          Only then a mainline DT describing the hardware starts to make sense. And still it will take years until most hardware features eventually work so why should board makers even consider going this route since it’s a massive effort and provides their users only a limited subset of working hardware features for years.

      2. IMHO the kernel pieces for rk356x are already there, there’s a few rk356x boards working well (enough for me at least) on armbian 5.19 kernels including rock3a, but yeah I suppose those are still patchsets.

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