Re: Crucial MX200 1TB - Write performance is minimal? Help
As far as I know Apple don't allow trim for third party SSD's without using hacks. And video editing (due to the large amounts of data being written) is the one usage where you'd definately need trim and the drives own garbage collection is likely to be insufficient.
I'm not a Mac user so I can't much help but try googling for enabling trim in Mac OS