When you say “here’s a 5GHz CPU” you expect it to fit with the current product lineup and to have thermal and power requirements within certain parameters that would allow you to run the thing at 5GHz without much effort.

“We overclocked this CPU to 5GHz” means all bets are off. You often have some headroom to overclock on stock voltage/cooling but always need to go above and beyond for more extreme overclocking. This particular setup apparently was using a very fancy 1700ish W chiller, and a 1300W PSU for the chassis itself.

Also, this is a Xeon part, so one you’d expect to see in servers or workstations. You don’t want that sort of thermals anywhere close to a data centre rack, and the sort of business with the budget to give you this sort of CPU wouldn’t want to have their IT department assembling custom coolers like this.

All of this assumes, of course, you can run the chip stably. That's more or less a given at stock speeds, operating within the vendor's operational specs. Once you start overclocking, all bets are off. Extreme overclocking (the sort that uses liquid nitrogen or this sort of chiller) never lasts long. Again, something an enthusiast overclocking for a few FPS on a gaming rig might be willing to live with, but a problem that's seriously disruptive in the sort of environment a Xeon is likely to be deployed.

(EDIT: Fixed chiller power and added stability concerns)