Im not sure if it came with a fresh install rather than just an update, how would I find this out? I had been thinking about a reinstall but it seems like a bit of a task.
As for TRIM again how would I find this out?
I'm not quite sure how you would find out if you're on a clean install or update, etc, but it is always good practice to do a clean install of any OS when you buy used because you've no idea what the previous owner might have put on there, that sort of thing. Maybe that's a different story if you know the person though.
Anyways for TRIM click the apple dropdown menu in the upper left hand corner and select about this mac.
On the overview tab (default tab when you open it) you will see a button for "system report", click that.
Under Hardware in the left column select SATA/SATA Express, look for "Trim Support" listed in the right hand bottom column, it should indicate YES, or NO. If it's yes, it's on, if it's no, it's not.
From here if you still need to enable it you can 1. enable trim force by opening terminal and typing "sudo trimforce enable", hitting enter, and restarting (more
here), or 2. install a TrimEnabler (third party software).
Having TRIM disabled on some SSDs can really cause a lot of beachballs, as I've experienced that myself after forgetting to enable TRIM on a clean install, so hopefully this is the problem and possibly saves you a full reinstallation.
