"Noctua, a corporate collaboration with nearly ten years of
experience, has become the very definition of high performance, silent
cooling hardware. With innovative features that many cooling
manufacturers have yet to even consider, such as notched blades to
reduce turbulence, self-stabilizing oil-pressure bearings, and their
torque-pulse reducing SCD, Noctua is a true force to be reckoned with.
Recently, however, Noctua has developed a new, previously unthinkable
product - that of the NF-P14 FLX. If you can increasing the diameter
of the propeller, while simultaneously reducing RPM, you should be
able to produce a similar amount of air flow, while keeping the fan
nearly silent. Noctua took that idea and ran; the NF-P14 FLX is one of
the only fully contained fan units that allows you to effectively
install a 140mm fan into a 120mm mount. Let's see if the tech is worth
the 'Noctua tax'."