FrostyTech posted a review on the Noctua NH-U9B Low Noise Heatsink
A quote from the article:
>> Noctua NH-U9B Low Noise Heatsink Review
The Noctua NH-U9B is a refined take on the previously successful NH-U9 heatsink. This time around, Noctua nickel plate all copper surfaces and bundle in the super quiet NF-B9 fan - and it's not your average vaneaxial fan either. The NF-B9 is a flesh-toned fan with three key innovations; SSO bearings, vortex-control notches, and textured leading impeller surfaces.
>> Noctua NH-U9B Low Noise Heatsink Review