In general, TRIM is the first line of defense in keeping your SSD alive. There is, of course, no sense in trying to enable TRIM if your hard disk does not support it.

Pretty much every operating system in use these days supports TRIM—a special ATA command that the OS sends along to an SSD when deleting files on that SSD. The lone exception to that list has ...

By default, OS, unlike Windows, doesn't automatically enable the TRIM command for a self-installed SSD. (If your Mac comes with an SSD, TRIM will already be enabled.) ...

Apple has begun enabling TRIM support in its latest OS update if you install a third-party SSD -- but be advised, some SSDs don't work with the chosen method of TRIM.