This Raspberry Pi Mini ITX Board Has Tons Of IO

The Raspberry Pi now comes in a wide variety of versions. There are tiny little Zeros, and of course the mainstream-sized boards. Then, there’s the latest greatest Compute Module 4, ready to slot on to a carrier board to break out all its IO. The Seaberry is one such design, as demonstrated by [Jeff Geerling], giving the CM4 a Mini ITX formfactor and a ton of IO. (Video embedded after the break.)

The Seaberry sports a full-sized x16 PCI-E port, with only 1x bandwidth but capable of holding full-sized cards. There’s also four mini-PCI-E slots along the top, with four M.2 E-key slots hiding underneath. The board then has a M.2 slot in the middle for NVME drives, and x1 PCI-E slot hanging off the side.

Ports include a USB 2.0, a Cisco-style serial console port, two HDMI ports, and a Gigabit Ethernet jack. Two seperate 12V connectors are provided allowing for a redundant power supply setup, which can be made triple redundant with the addition of the right Power-over-Ethernet hardware. Naturally, the Seaberry also features the usual 40-pin GPIO header, the 14-pin CM4 IO header, as well as the usual DSI, CSI and RTC hookups.

The Mini ITX design is a particular boon. The Seaberry can easily be slapped into a mini PC case, and the power button and activity LEDs work just like you’d expect.

In testing the board, [Jeff Geerling] filled up almost every slot, trying to see how many cards will run on an Compute Module 4 with 8GB of RAM. Throwing in an NVME SSD drive, several Coral TPUs for machine learning, multiple network cards and a SATA interface caused no problems.

Not everything worked due to driver limitations, but everything enumerated on the bus just fine. [Jeff’s] earlier work paid dividends here. His previous attempts trying to get GPUs working on the platform meant opening up an extended BAR space for PCI devices wasn’t a problem.

Further attempts involved adding in a 12-card carrier loaded up with 7 more TPUs, 5 more WiFi cards, and 3 more NVME drives. Outside of some kernel panics from excess NVME drives, the Pi CM4 was still able to detect everything, showing it can address more than 20 PCI-E devices without major issues.

Throwing so many devices at the Pi CM4 may not have an obvious application in the mainstream, but it’s sure to prove useful to someone. We’re certainly enjoying watching [Jeff] push the limits of what’s possible with the CM4, and we hope he gets GPUs working soon.

26 thoughts on “This Raspberry Pi Mini ITX Board Has Tons Of IO

  1. I dont get it. $435 for this. Why would you want to do that? You can get an amd or intel miniitx with full width pcie and a whole lot more power. I could see if the board was cheaper, but thats a lot of money.

    1. This is a development platform. They are specialised and low volume and therefore the high cost.
      If you want to develop something with using a CM4 module then this board is for you, it is not for the general public.

      1. Maybe? If it had schematics/layout, sure. But usually boards like this are starting points for custom designs, and without those, much less useful. Unless they’re planned? Couldn’t see them anywhere.

    2. It’s also a Mini ITX build that doesn’t seem to fit in an ITX case vertically. I say “seem” because i didn’t watch the video because I don’t see the point. If I’m wrong I’m sure someone will correct me.

        1. I’m quite surprised this isn’t more popular.

          I mean, something like this could be harnessed as a router that can blockchain its way to a private internet. It can have distributed computation with the Coral boards and the inevitable FPGAs/GPUs that can be plugged in as well as a Crypto ASIC and lots of storage.

          Get 1000 of these distributed and set up with that intent. And watch the Masters of the Universe shudder.

          1. RPI is a silly platform for mining. GPUs are big ticket items in both price or power, so RPI isn’t going to save much either way. A standard PC platform with mining software makes a lot more sense. 1:6 PCIe expansion cards are available at $50. (I though I saw some 1:10 switches the other day)

          2. I mean just a retired type asic that can just do basic synch node crunching. It wouldn’t be about mining at all.

            Too many people think of blockchain as ONLY a money/coin thing. Chains like Etheteum and it’s derivatives could be harnessed for distributed servers for gaming, social networking, and enterprise.

            I could see a router that hosts a node that is simply a web3 dns type server for a future private internet.

          3. Also, having connected processing power would allow large distributed systems to crunch simulations and such for paying customers. Maybe Boeing offload CFD, and NOAA offloads weather prediction…

            I wish HAD ran a Kickstarer for this type of project.

      1. Yeah, I don’t understand the form factor. The IO access is a big hole, there’s no lid. What’s the point of the case? You’d might as well nail it to a board. Then they could advertise it as 2×6 form factor.

        1. I would have made an I/O panel a black PCB with the correct holes milled out and silk screen label. It wouldn’t have the usual springy fitting as pressed metal ones. A couple of L brackets to the motherboard to hold it in place and it would look semi-professional.

          For an “open chassis” development system, all you need is a few standoffs and screws to lift it off the table.

  2. “Just because we can do something, doesn’t mean we should.” because in effect this board is hanging 11 PCIe ports of a single “x1 PCI Express gen 2.0 lane” (total maximum data throughput 400MB/sec) in my mind that is just silly.

    1. Why? God knows I would LOVE to have the spare dollars to throw at this. I would give my Kingdom for a good ultra low power storage server, and this thing would take the cake. Standard form factor, low low power consumption, plenty of places to connect NVMe drives.

    2. It’s for development purposes, not production (though one could probably use it in production if they really wanted to). If you’re trying to design a custom solution based off of a CM4, you’d want each type of PCIe physical interface available for prototyping. It’s only “silly” if you don’t know what it’s for.

        1. No, I mean multiple concurrent connectors available at the same time on one board without having to resort to risers. It’s a special purpose board, which is plainly obvious to anyone who actually knows about prototyping embedded applications.

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