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Take two snapshots of the same liquid-cooled server rack, and the thermal conditions can look identical. Rack power, coolant supply temperature, and processor temperature are nearly unchanged.

But beneath these stable operating conditions, the cooling loop may be struggling to keep up with the heat. In the later snapshot, the coolant distribution unit (CDU) drives the pumps at a higher speed while the filter consumes more of the available pressure budget, and the flow of coolant in one branch has started to slow down compared to its peers. The processors are still being cooled to the temperature required for the data center, but the cooling loop is working harder to prevent overheating.