2010 Mac Mini Downgrade I have a 2010 Mac Mini with no DVD drive and a 5,400 RPM hard drive. Of late, it's begun to get quite sluggish, and I'm fairly sure it's the slow HDD that's to blame.

I took a look at the means of upgrading it, but since it involves practically taking the entire thing apart to get to the hard drive, I decided it wasn't something I wanted to do myself.

My first option is to simply do a complete format of the machine (I only really use it for Plex media streaming), and see if that helps speed it up. This hasn't been done in the few years I've owned the Mini, I've just always kept it updated, and I guess it may have become bloated (though there's not much installed on it).

My second option is to attempt to downgrade the Yosemite install that's currently on it back down to something older (and presumably quicker). I can probably go back as far as Lion/Mountain Lion if need be, combined with the full format. So basically revert to stock Lion, re-install Plex, and away I go.

So, a couple of questions:


In this situation, is a complete format / re-install of Yosemite likely to help? If so, will the recovery partition handle this?
If not, what's the best means of downgrading back to an older OS such as Lion, and if I do this, am I likely to see speed increases purely because the older OS's are less demanding? Can I make an installer on a USB stick, since my Mini has no disc drive?
So I made a Mountain Lion boot stick, wiped it, reinstalled fresh, and it's blazing fast again. Either Yosemite / Mavericks beforehand had slowed it down, or the drive itself had just become very fragmented / clogged / heavy.

All good now, I'd forgotten how nippy the thing can be!