Hey guys! I've just moved from PC to MAC and very happy so far, except a few ridiculous issues. I will probably post a full list of useful things I had with Windows and lack with OSX, but not today. Today my question is, where OS is installed on SSD, I still hear HDD up and running, when: 1. iMAC is starting (well that's understandable, though I don't see the reason why not prevent it) 2. Occasionally with no reason it starts then stops in 15-20 min 3. I open some apps My understanding was if every OS file is on the SSD drive why bother to start HDD. First its noticeable, I can hear its working, a sort of humming noise, not loud, but still. And second, every unnecessary start/stop will probably lead to hard drive failure in the long term, again why start it? I hope someone will suggest something.