Dual Gigabit Ethernet Carrier Board for Raspberry Pi Compute Module 4

I was in the same camp, but I bought a raspberry pi400 recently, and I have to say, I really like that unit... (I have not tested it as router though).
Regarding routers, I wonder about using a compute module with the matching IO/board and use the PCIe slot to add a NIC, potentially an intel multiport NIC (probably not, still have a single port intel NIC sitting in a box somewhere) :wink:

Which would be a poor choice hardware-wise given the rather lackluster connectivity of the RPi4 SoC.

Honest question, why is the PCIe slot available in the Pi4 CM/IO board combination not sufficient for a dual gigabit ethernet NIC? A PCIe 2.0 1x slot with 5 GT/s (per direction) should be sufficient for Gigabit ethernet's expected ~1GT/s per NIC, no?

Single port will probably work however multiport will be much of a stretch at least looking att Jeff Gerlings results. It can barely do 2.5Gbit with jumbo frames less than 2Gbit with.

This also seems to be in line with his testing of HDDs (bandwidth)

Mmmh, he references an earlier attempt where he transferred 4.15 Gbps through a 4 port intel ethernet NIC... Extrapolating from that I think two 1 Gbps devices should work out, barely.
I know that you seem to dislike the Pis (or probably rather consider other contenders in the same price bracket better/preferable) and you probably have good reasons for that, but I am unsure whether for the specific use-case I laid out your presented rationale is all that fitting.

Multiport would at least scale up to 4-ports which clearly wouldn't work, at least not to their full potential.
The Pi have their strengh but they're a poor choice for networking and its one of the reasons you have alternatives such as Marvell and solutions based on Rockchip SoCs instead which are better suited.



The CM4 router is compatible with most systems that support Raspberry Pi 4, but most Linux distributions do not optimize the network device scenarios. So OpenWRT is recommended.

  • Download Address
    • OpenWRT Official version
      OpenWRT 21.02 will be released soon, before that you can choose from the following two versions
    • DFRobot Version
      Based on the latest development version of OpenWRT, which already includes the web interface and language pack, it is recommended to get started
    • OpenWRT official snapshot version
      The official snapshot is the smallest system, using serial terminal control, you need to manually install the Web console, driver, etc. it is recommended for experienced users.

yes, but out-of-stock and 50% more expensive (45 vs 30$) no doubt due to chip shortage crisis...


for now i am forced to get their other cheaper single lan io board, until the other available

PiTray mini for Raspberry Pi Compute Module 4

what's the PiTray mini's advantage over rpi4 standard (as both feature single lan)?

it a quite small and cheap board

but if you add up the cheapest cm-lite you surpass the rpi4's price and you get a lower spec (1gb vs 2gb of ram and no USB3 !) sbc with a need to build a custom case & cooling - no thanks

yes, indeed

here we dont get the Pi stuff at the actual prices it almost double in some cases

here is another possible option but you will have to make the board add PCI adapter

some updates https://www.cnx-software.com/2021/08/02/raspberry-pi-compute-module-4-mini-router-keeps-cool-with-aluminum-alloy-cover/


Check out the Dfrobot carrier board. It uses PCIe for the second Gigabit Ethernet port. They also sell a case for this board.

Seems like a Rube Goldberg attempt at a NanoPi R4S when all is done. By the time you buy the carrier board, the compute module, the case... If I was sitting on an unused compute module I wanted to give a second life I could maybe see it.

This was already shared in my post Dual Gigabit Ethernet Carrier Board for Raspberry Pi Compute Module 4 - #21 by maurer

There are performance tests regarding the Dfrobot carrier board?