I have a 2012 rMPB 15". When I first got it, OS X booted up in about 25 seconds. I noticed it getting slower, so I timed it -- it was now taking about 65 seconds. Pretty quick, but almost 3 times slower. The battery was 100% charged, plugged in, there weren't any peripherals attached, and I had shut down all my applications before re-booting it. I was curious as to why it was slowing down. I ran some benchmarks and speed tests and my results were consistent with the benchmarks I did when the machine was brand new. I decided to do a fresh install of ML and see if anything changes. After the install, before I restored from my time machine backup, I tried shutting it down and re-starting it a few times (in the same manner I had before), and it was still consistently taking about 65 seconds to boot up. After restoring from my time machine backup, it is still taking 65 seconds. Has anyone else noticed this with this machine in particular (or any Mac for that matter)? I have never experienced any Apple computer slowing down like this. Is there anything that can be done to fix this? My fear is that as time goes by it will get slower and slower. Any comments/suggestions would be much appreciated.