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geerlingguy
Add Waveshare CM4-DUAL-ETH-MINI board
The Waveshare CM4-DUAL-ETH-MINI board is similar to the DFRobot IoT Router Carrier Board Mini, but with a 40-pin I/O header and a USB 2.0 type A port instead of USB-C.
I think this board might be nearer to the DFRobot IoT Router Carrier Board Mini than the other alternatives. Waveshare documentation seems to indicate that it is using kmod-r8169 for the second ethernet port, similar to the DFRobot board.
@mayniklas maybe you could share your experience with this board, as I found your project https://github.com/MayNiklas/openwrt-pi-cm4? 🚀
I think this board might be nearer to the DFRobot IoT Router Carrier Board Mini than the other alternatives. Waveshare documentation seems to indicate that it is using
kmod-r8169for the second ethernet port, similar to the DFRobot board.@MayNiklas maybe you could share your experience with this board, as I found your project https://github.com/MayNiklas/openwrt-pi-cm4? 🚀
The board uses a PCI-e NIC for the second NIC. I personally really like it: it has great documentation and was quite cheap in Europe (30€). It's also easily available around the world. A friend helped me designing a 3D printable case we will soon publish.
Running NixOS (declerative Linux distribution), everything worked out of the box. Together with @pinpox, we are working on a NixOS router using this hardware: https://github.com/pinpox/nixos-raspberrypi-router
My biggest complaint: the second NIC creates a high single core load. I noticed a big jump in CPU interrupts. Compared to the integrated NIC, the CPU load this NIC causes is around 10-20 times higher. -> around 850-900 mbit will be the limit without overclocking the Pi -> might be able to figure out some tuning
Contact me in case you need any specific tests!
In case anyone is interested, I created a 3d-printable case for this board.
When it comes to networking performance and CPU load, I would recommend this blog post. This is not about this exact board, but a similar board with the same PCIe Realtek NIC. In that post the author assigns the different interrupts to individual CPU cores to distribute the load more evenly. He also enabled interrupt coalescing, which reduces CPU load quite a bit. I did the suggested optimizations and can confirm the author's conclusion, that the CM4's internal NIC causes a much higher CPU load than the Realtek one, which is barely noticable. Overall I like the board and it has been working quite well for me.