A cage[0] is ~100x larger than what you need to host a single server. Many data centers will colocate by the rack unit. At others you can get a quarter or half cabinet[1]. Even at the very largest enterprise datacenters you can colocate a single cabinet.
[0]: https://static.cisco-eagle.com/images/category/WireCrafters/...
[1]: https://www.edpeurope.com/wp-content/uploads/EDP-3-Compartme...
> A cage[0] is ~100x larger than what you need to host a single server.
Yup, but i was assuming that he wanted to experiment building gpu rigs. For sure standard GPU servers are cheaper and easy to maintain. I have two lenovos, bought them used, already EOL.. was cheap and better than any custom gpu rig.. but i was pragmatic, because my goal was to put it in production, and not to research...
You could fit 10 million dollars of GPU rigs in the smallest of cages. A cage is an entire room. You don't need that to run a few servers.