FrostyTech posted a Verax Quattro 1 Ultra-Quiet Heatsink review
The Verax Quattro 1 is a large squarish heatsink, accented by two specialized fans which produce barely a whisper of noise. Six copper heatpipes extend up from a large copper base through a cube of aluminum cooling fins, as is popular with many silent heatsink designs. A multi-socket mounting bracket makes it possible to use the Quattro 1 with just about any processor platform. The two Verax ultra-quiet CAIRdB fans are the real selling point of the Quattro 1 heatsink however, and under power both fans generate less than 31 dbA according to FrostyTech's own measurements.Verax Quattro 1 Ultra-Quiet Heatsink Review