No secret, I help friends update the performance of their old Macs. Aside from bumping RAM or upgrade operating systems, I will often recommend the replacement of a spinning hard drive with a modern solid state drive (SSD). Using apps like SuperDuper or CarbonCopyCloner, its easy to back up their data and then install a fresh system on a new SSD, which helps to recreate the recovery partition.
After migrating user accounts and data back to the new drive, I like to enable TRIM, if the SSD supports it, which most do. To do so, open Terminal.app and paste in the following line:
sudo trimforce enable
You’ll be warned that data loss could occur, but I have yet to find an issue with dataloss on any SSDs I’ve done this with. Press y to continue. That’s it.
If you want to see the TRIM status for your boot drive, execute the following Terminal command:
system_profiler SPSerialATADataType | grep ‘TRIM’
Hopefully yours says “TRIM Support: Yes”. Or, if you’d prefer to view the status in a Mac application, you could select the Apple icon in the upper left corner of your screen, choose About This Mac->System Report…, and then choose SATA/SATA Express and scroll down until you see TRIM Support on the right hand pane (note: you also might need to select the drive you’re curious about in the upper right hand pane).