Gathered together here are the specifications for the fans being tested for this review. You can see that someone has been thinking hard about the specs of these fans. For example, the PWM fans have a maximum speed consistently higher than the FLX fans. Considering that the variable speed of a PWM fan only maxes out when the demand is greatest, and the fan usually runs at an intermediate speed, having the higher headroom makes sense – it is quiet most of the time but has the extra output when you really need it. If you don’t need that max, Noctua sends you a Low Noise Adapter that limits the speed the fan can go.



Another point to ponder is this: Noctua provides you with the static pressure of each fan with each intermediate setting. This is the kind of fine-grained specification you don’t often see with other brands.