@MarkAB @squareflair @jbond @glyph @SwiftOnSecurity Some Cray and Control Data mainframes of the era also had water cooling. It was a little unnerving as a programmer to get a tour in the datacenter and see the interior of a CDC 6600 with the water circulating and multiple oscilloscopes connected while the system was running. We're now coming full circle in cooling large systems. FYI, tape and disk drives, and PDU's usually took up more spaces than the processors.