In the design and development of axial fans, the three aerodynamic key parameters of airflow, pressure and noise play a major role. Usually, the goal is to achieve the amount of airflow and static pressure required by a specific application at the lowest possible noise emission. The design should hence provide the optimal balance of airflow, pressure and noise for a given application.

However, even in the field of PC cooling, each application has different requirements: Whereas CPU coolers with tighter fin-spacing require high static pressure, it's mostly the airflow to noise ratio that counts when it comes to case fans.

Common fans are usually designed to be all-round solutions with compromises in certain areas in order to achieve solid results in all typical applications.

Noctua, on the other hand, is following a two-fold approach with its S12 and P12 fan series in order to achieve optimal results at various applications: While the NF-S12B was optimized so as to provide a class-leading airflow to noise ratio and therefore makes for an excellent case fan, the NF-P12 was designed to produce high airflow and an outstanding amount of static pressure, which makes it perfect for use on CPU coolers and other high-impedance applications. The following illustration shows how this approach differs from common all-round solutions:



While the NF-S12B delivers less static pressure, it provides a better airflow/noise ratio. Therefore, it's perfectly suited for case ventilation as well as all applications which don't demand high static pressure and where maximum quietness is the first priority. The NF-P12 on the other hand provides a better pressure/noise ratio and should therefore be the first choice for all applications which demand high static pressure such as CPU cooling.













Links:
  NF-P12 Nine Blade Design with Vortex-Control Notches
  NF-S12B Blade Design with Bevelled Blade Tips
  Which fan is right for me?