Watercooling is exactly "silent" either, but with watercooling, you can take your processor past the limits of air cooling. Pumps are usually very reliable if you buy from the good brands like DangerDen, Swiftech, Iwaki, Ehiem. Watercooling isnt supposed to be portable, but people have squeezed watercooling into the Aspire Q-pack and some other ones too. Pretty cramped.