MadShripms have published 17-Way roundup of 120mm fans from different manufactures. They tested their performance both temperature as noise wise - and include sound samples of the fans running at different voltages so you can compare them head to head. Are all fans created equal?

In my hours of testing I've learned that numbers aren't everything; a dBA value won't tell you if there is a clicking noise, buzzing motor or another irritating noise which the dBA meter simple doesn't pick up. CPU temperatures are an okay method to see how much air is moved but it's not perfect either. If you're looking for a silent case fan only a slight bit of air movement is enough for the device to fulfill its purpose.

If you're building an extremely silent system there are some excellent choices available for you, so you don't have restrict yourself to one product. The Nexus, Aerocool, Scythe "E", Coolermaster Ultra Silent and GlobalWin can all become whisper quiet at different voltages without any disturbing motor noises.

If you're looking for a decent CPU fan you can't go wrong with the Papst 4412 F/2GLL, but it has some stiff competition from the mCubed X12 and Scythe "E", the Spire's numbers at 12v place it on par with the previous two, only if you place your ear next to the fan you will hear a difference, but the subjective listening tests are just that: subjective. Your experience with certain fans can differ from mine.

If you are not into extreme silence but don't want to go overboard either in the noise department the Acoustifan Ultra Quiet offers excellent performance, the Arctic Fan 12 with its integrated anti-vibration kit also delivers quite well at different voltages. If you want flashy lights Coolermaster's LED silent will suite you perfectly although it's overshadowed in *bling* by AC Ryan's BlackFire4.