Fans.

No matter the cooling you have, you need fans. If you air cool, you obviously need them for your heatsink, as well as case airflow. If you have water cooling, you still need someway to cool down the radiator -- fans. Even more extreme methods still (usually) have fans for airflow for parts not being sent on a cold trip (ie hard drive, GPU, etc).

Up until fan technology took off, you could only pick two of the following qualities in a fan: quiet, high airflow, looks, and price. The decibal rating is quite straight forward; the lower the number, the less noise it makes. This is usually personal preference and location your computer. Most people are not fans (Ha! Puns!) of having 50+dBA fans in their computer if they sleep in that room as well. High airflow is another trait that is obvious - but being tied to the decibel rating usually means you can only have one or the other. Looks and price don't bare need to be explained, either. (I hope.)

SilenX seemed to come out of no where with their fan series, dubbed SilenX IXP. The little known company claimed that it had the best airflow to noise ratio of any other fan, which caused quite a stir in the cooling community. Here are the official specs of this particular fan:

Name: SilenX IXP-76-18
Fan Size: 120mm
Max RPM: 1400RPM
Airflow: 90CFM
Noise Level: 18dBA

Now, I'm not sure about you, but when I first glanced at those specs, at the same time as I was thinking it was too good to be true, I was reaching for my credit card.

So, do they stand up, or are they another bluff in the fan cooling arena?