Liquid at the Chip
Direct-to-chip cooling is less an invention than a relocation. Pumps, heat exchangers, filters and pipes are old equipment; what is new is that they now run to the rack, with a coolant distribution unit acting as the firewall between clean server plumbing and dirtier building water. The efficiency case rests on temperature: a cold plate can work with warm supply water, and warm water can be cooled by dry coolers without refrigeration for much of the year. Faraday's read: direct-to-chip is the default because the accelerator vendors ship it, and immersion remains a specialized option. The real question for most buyers is not which liquid method but how fast their buildings can accept liquid at all.
Knowledge check
What does a coolant distribution unit separate, and why does that separation matter?
Show the answer
It separates the small technology cooling system that runs through the servers from the larger facility water system that serves the building. The separation lets operators keep the server loop clean and chemically controlled, protecting the fine channels in cold plates, and it limits how much liquid could leak near electronics.