My new Macbook Air 2012 model with Mountain Lion installed. It has been super loud all the way. It was quite mysterious because the CPU usage per app has been below 10% and most apps including safari have been using like 0.X%. So I was out of clues until I accidentally closed Safari and the whole world suddenly quiet down!!! Then after a few back and forth tests, I confirmed that it was safari alone that caused all the noise. I started using Chrome since and even though it's more memory/CPU hungry it never made any noise! Anyone knows how to deal with this?