They have precision dry break quick connects. They use crazy jacketed hoses with PTFE liners and copolymer sheating, sometimes with reinforcment layers. The coolant is pumping through at an operating pressure of 10bar @ 200C. These applications exceed the limits of potable water and hydronic heating systems
Something closer to 30C or even 40-45C (the latter if you're in a hot and humid location like Florida and want to get by without refrigeration technology and just increasing the flow rate/heat exchangers) is more realistic for datacenter-scale component-level water cooling.
Yeah, a high-power-density Nvidia chip may need colder water in the 20-30C range, but CPUs and such aren't efficient at the clocks that cause power densities where you need <<40C water.
My 5950X is running at ~30C (return from the radiator) water and 4.5 GHz (maybe even a bit more? I don't recall, the heat wave around here is over) on a torture test with Prime95 where it produces almost double the nominal TDP (thermally limited, due to a few hot-running cores and around 80-85C average core temperature on the others). The base clock is at just 3.4 GHz.
I see phase-change cooling with nucleate boiling as well as very tightly integrated (liquid) water channels in the future, with the latter thinning out the die to weld or solder a better thermal conductor closer to the actual transistor junctions, with minimal distance to the coolant.
How does the coolant get to 200c, that'd imply some sort of inline heatpump right?