Hi, I wonder if this is normal: My iMac 27" i7 with a 2TB Hitachi disk seems to vibrate. It is so strong that it also makes my desk vibrate a little. If I hold tight on the desktop, it stops. However, the noise/hum is clearly audible when I put the iMac on the floor, for example. Apple is happy to replace it, but am I too picky? Anyone else with the same? (FWIW, I'll describe the noise as if you mount a hard drive in a cabinet, and it isn't really fastened/isolated well enough.) I tried the smcfancontrol and checked the fans, and its not them, the noise is constant even if I set them to max or min. And it disappears completely when the disk has spun down. My Macbook Pro, Macbook, or other apple hardware I got with a HDD does not make this kind of noise. How silent is your iMac compared to your macbook/macbook pro?