FrostyTech has posted a NoiseControl Silverado Heatsink review

You see, the idea behind the Noisecontrol Silverado is that the silver base spreads the heat more evenly over the aluminum extrusion which is cooled by twin squirrel cage fans. The two fans come with an assortment of different connectors which lower the voltage to the motor, and thus limit their speed. Users looking for a high-performance heatsink will find the Silverado is not quite up to expectations. Users looking for a good performance heatsink with low-noise properties (and lower frequency motor noises) will appreciate the Silverado and what it can do for them.

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