Comment by otter-in-a-suit

You'd be delighted (or terrified) to know that I just added an old gaming computer in a 4U case to the cluster, so I can play with PCI/GPU passthrough.

The Dell is essentially the main machine that runs everything we actually use - the other hardware is either used as redundancy or for experiments (or both). I got the Pi from a work thing and this has been a fun use case. Not that I necessarily recommend it...