Tried to OC

[Ommid]

much diff between 28 and 36db?

[Webby]

dB are a funny thing but basically its a logarithmic scale so an increase of 10dB is doubling the sound pressure (and hence the volume) so theoretically the is almost a doubling in noise levels between those fans.

The next thing to remember is that the the dB level will depend on the conditions in which it is measured and how far away from the source it is measured. The upshot of this is you have to take manufacturers data with a pinch of salt.