Booting from an external ssd?

[Stratoandrea94]

Hi! I have been reading some discussion but my dubt is still living. Last year I bought an Imac and maybe I made a mistake, because mine doesn't have an internal ssd (or fusion drive) and it runs a bit slow. Yesterday I discovered a guy that with an Usb 3.0 enclosure and a Samsung 840 evo had a read/write speed on the disk that reached 400 Megabyte/s but in this way there is not trim support.
I would want to boot from that disk but without trim is safe?

 

[Weaselboy]

Hi! I have been reading some discussion but my dubt is still living. Last year I bought an Imac and maybe I made a mistake, because mine doesn't have an internal ssd (or fusion drive) and it runs a bit slow. Yesterday I discovered a guy that with an Usb 3.0 enclosure and a Samsung 840 evo had a read/write speed on the disk that reached 400 Megabyte/s but in this way there is not trim support.
I would want to boot from that disk but without trim is safe?

It won't ruin the SSD or anything, but potentially over a long period of time the write speeds may slow because of the lack of TRIM.