I have not had a lot of luck finding an answer to this question through searching around, so I thought I'd pose it here. I'm happy for a re-direct if someone has responded to this before. The TRIM Enabler application available for download is intended to activate TRIM on non-Apple-installed SSDs. So, if you install a SSD where the HDD was in your MacBook Pro, you can turn TRIM on within this program. That's great. You now have an SSD and maybe an HDD within your laptop, or you've moved the HDD outside as an external. I've got a slightly different scenario. I would like to put an SSD in an external enclosure which is attached via USB 3.0 to a retina MacBook Pro. TRIM is already enabled on the internal Apple-endorsed SSD within my computer, but TRIM is not natively enabled in the external SSD. If I use TRIM Enabler to activate TRIM on the external, will I mess up some of the settings Mac OS uses to recognise the 'native' internal SSD? Does anyone have any experience with this? Thanks!