For anyone interested in playing with distributed systems, I'd really recommend getting a single machine with latest 16-core CPU from AMD and just running 8 virtual machines on it. 8 virtual machines, with 4 hyper threads pinned per machine, and 1/8 of total RAM per machine. Create a network between them virtually within your virtualization software of choice (such as Proxmox).
And suddenly you can start playing with distributed software, even though it's running on a single machine. For resiliency tests you can unplug one machine at a time with a single click. It will annihilate a Pi cluster in Perf/W as well, and you don't have to assemble a complex web of components to make it work. Just a single CPU, motherboard, m.2 SSD, and two sticks of RAM.
Naturally, using a high core count machine without virtualization will get you best overall Perf/W in most benchmarks. What's also important but often not highlighted in benchmarks in Idle W if you'd like to keep your cluster running, and only use it occasionally.
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