Turing Pi has announced a new cluster board, this time for the recently-announced Raspberry Pi Compute Module 4. The Turing Pi 2 promises high performance, despite its compact mini-ITX form factor.
https://www.notebookcheck.net/Raspberry-Pi-Turn-the-Compute-Module-4-into-a-cluster-system-with-Turing-Pi-2.498870.0.html