Products | Technologies | Support | Press | Reviews | Where To Buy

Smooth Commutation Drive

Next to aerodynamic noise and bearing related noises, the so called "commutation noise" or "switching noise" can play a major role in the noise emission of axial fans with brushless DC motors. At each transition from one stator coil to another, the rotor receives a sudden torque pulse when the next coil switches on. Each of these torque pulses causes a minute deformation of the whole fan structure. Depending on rpm, torque and the material of the fan, this can result in noticeable noises.

Noctua's Smooth Commutation Drive system provides more continuous switching in order to achieve a smoother transition between the stator coils and thereby significantly contributes to the fan's overall quietness. The second generation of this technology (SCD2) further improves running smoothness and reduces minute noises in close proximity to the motor.

20.10.2014 - TechTesters NH-L12
Test verdict: "De NH-L12 is net als zín broertjes en zusjes bedoeld is als een product voor echte liefhebbers die graag iets meer uitgeven om net die beetje extra prestaties te halen, of die de typische Noctua-ervaring reeds waarderen, en met dat in het achterhoofd doet de NH-L12 het zoals verwacht uitstekend." (Stephan Overbeeke, TechTesters)

20.10.2014 - NF-A8 PWM
Test verdict: "Dla bardziej wymagających użytkowników polecam zainteresować się tą serią." (Paweł Borysewicz,

19.10.2014 - NF-A4x10 5V
Test verdict: "Devido a tudo isto a Noctua NF-A4x10 5V ť um produto recomendado pelo InsideGeeks!" (Nuno Ferreira,

19.10.2014 - NH-D15
Test verdict: "True to Noctua form, the NH-D15 is virtually silent - and the volume level is even quiet managable at 100% fan speed (~1500rpm). The cooling performance of this monster actually bests all but two of the liquid cooling systems and every other heatsink we tested." (Benjamin Heide,