> manufacturers in different memory banks, but since it's always > possible to power down, replace or just remove memory, and power > up again,
Hmm... "always"? What about long running computations like that simulation (or LLM training) launched a month ago and that's expected to finish in another month or so? Some mainframes have supported hot (un)plugging RAM modules as well and I wouldn't be surprised if some x86 servers also support it nowadays. Stefan