ThinkComputers.org has posted a preview on the SilenX IXTREMA Pro Fan Series

Everyone has fans in their system, even people running water cooling, the only exception you may find is someone running a vapor cooled system. In any case you want something that will keep your temperatures low and for some the added benefit of quietness is a major plus. Myself I don't mind listening to fans howl at high speeds, but some enjoy the bliss of a nice quiet system. The two fans I will review have been optimized for noise to airflow ratio, the lades have a forward swept design, the motor has a reduced size and shape to allow a larger surface area of fan blades and improve the aerodynamics also something which is exclusive to them are the fan mounts which are silicone-composite which dampen vibration.

SilenX IXTREMA Pro Fan Series Preview