Elite Bastards posted a review on the Noctua NF-P12 cooling fan

Interestingly, unlike the NF-S12, the NF-P12 has been designed more specifically with CPU coolers and water cooling radiators in mind than general chassis cooling, although cases with tight fan grills are also mentioned as an ideal application for this particular fan. "Why?" I hear you ask - Quite simply, because this particular part and its nine blade design has been produced with increased air flow and pressure in mind. Overall, it finds itself with many of the same benefits as Noctua's previous fans, with a motor that should reduce torque variations to keep the fan running smoothly (dubbed the Smooth Commutation Drive by Noctua) and a self-stabilising oil pressure bearing to keep the fan both quiet and with the ability to run stably for a very long period of time without failure.

Noctua NF-P12 cooling fan review