Hands up if you’ve got six Raspberry Pi Compute Module 4 boards lying around doing nothing — don’t all rush at once. For the one person in the back, there: DeskPi has revealed a $200 carrier board that will take your sextet of CM4s and combine them into some sort of machine-learning-Kubernetes cluster, in a Mini-ITX case, called the Super6C Raspberry Pi CM4 Cluster Mini-ITX board.
Standard-sized boards that take Raspberry Pi computers higher and further than ever before aren’t new, but this kind of six-node cluster is. Measuring 170mm (6.7 inches) square for a Mini-ITX case, it exposes pairs of USB 2.0 ports, HDMIs, and Ethernet sockets (plus a power input) to the outside world, attached to the first CM4, which acts as a management board.
Inside, every board gets a 5V fan header and a Micro SD card slot, as well as an M.2 2280 slot running at PCIe Gen 2 x1. This is not a spectacular speed, but it does allow each Compute Module to have its own SSD housed on the other side of the board to the CM4s.
Software support is vague, with just the word ‘Linux’ provided. Luckily, there are several kinds of Linux that run nicely on a Raspberry Pi CM4, and while Kubernetes prefers a 64bit OS environment, the official Raspberry Pi OS, Ubuntu, and more can provide that.
The DeskPi board is available from the DeskPi store for $199 plus shipping (it's also on Amazon for $249). This price includes the PCB itself and 100W power supply — hunting and capturing all of the CM4s is up to you.