It should be noted, though, that from physics perspective it makes sense to cram as much as computing power (although in case of MF, which unlike supercomputers do relatively simple calculations on high volumes of data, it rather means I/O throughput) into as small space as possible.

So having interconnected commodity servers will always be marginally more expensive to run than mainframe boxes of the size of fridge, which have dedicated hardware for interconnect of internal components (for example on-book CPU caches and shared RAM).