There's the clusterboard from pine64 which fits up to seven CPU boards: https://pine64.com/product-category/clusterboard/ https://pine64.com/product-category/cl

There's the clusterboard from pine64 which fits up to seven CPU boards: https://pine64.com/product-category/clusterboard/ https://pine64.com/product-category/clusterboard/ You can use two different CPU boards with the clusterboard: - SOPINE A64 compute module with a quad core ARM Cortex A53 and 2 GB RAM - SOEDGE AI NEURAL MODULE with a dual-Core ARM Cortex A35, a NPU IP from Verisilicon Vivante and 2 GB RAM Note that the pinout of the SOPINE/SOEDGE modules is not compatible with the Raspberry Pi 1 and 3 compute modules (DDR3 vs. DDR2 SO-DIMM socket and obviously a different pinout), so you unfortunately can't mix them. Pine64 also recently announced the SOQuartz module with a more powerful SoC (Rockchip RK3566 with four ARM Cortex-A55 cores, a Mali-G52 GPU and a 0.8 TOPS NPU), which uses the same form factor as the Raspberry Pi 4 compute modules. This might be an interesting alternative for future cluster solutions based on the new form factor. https://www.notebookcheck.net/PINE64-SOQuartz-Compute-Module-W-US-34-99-system-on-module-launched-that-can-be-used-as-a-Raspberry-Pi-Compute-Module-4-carrier-board.577956.0.html https://www.notebookcheck.net/PINE64-SOQuartz-Compute-Module...