Conduction-cooled liquid (primary/secondary loop)

The earliest documented direct-to-chip cooling in this dataset, a decade and a half before the term existed. The Numerical Wind Tunnel pressed a springy copper bellows against each of its 121 gallium-arsenide LSI packages per board, coolant flowing through the bellows to carry heat away by conduction rather than through an intervening air gap. That primary loop fed a secondary loop rejecting heat outside the building, the same two-loop shape a modern warm-water DLC facility uses. The mechanism this dataset now calls direct liquid cooling was not new in 2012: it was the only way to cool 1.7 GFlop/s out of a chip that ran hot enough gallium arsenide required it, and it was abandoned along with GaAs once CMOS density made air sufficient again for a generation.