2N
A capacity/path arrangement with two independent systems, each sized to carry the declared design load. 2N describes topology and capacity, not zero impact or a guaranteed availability outcome; shared dependencies and operating state still matter.
Current numbers
OEM/test-specific transientloss-of-cooling thermal-trip window for 1 kW+ GPUs — UPS-backed pumps + N+1/2N rejection mandatory
Project-specific BOM/TCO premiumMEP-scope construction-cost swing of 2N over N+1 for the same usable load; 2N strands ~50% of installed capacity
~50% / 2–3%battery-capacity cut and double-conversion-loss cut from distributed BBU + supercaps vs central 2N