[GTX 1650 – Internal or external SSD upgrade to IMAC 2012
Plug in a USB3 SSD and set it up to be the boot drive.
You can install a drive internally if you wish, but, be aware that there is a possibility of something getting damaged during the procedure.
You can get about 85% of “the speed” from the USB3 drive (that you would get from an internally-installed SSD).
In my opinion, the slight loss in speed isn’t worth the risk of opening the iMac — unless you’re absolutely sure of your abilities to do the job.
You should see read speeds in the 420MBps range from a USB3 SSD.
Either buy one “ready to go” (like the samsung t5), or get
– a “bare” 2.5″ SATA SSD
– a 2.5″ USB3 enclosure like this:
Inateck 2.5 Hard Drive Enclosure, USB 3.0 External Hard Drive Case, UASP Supported, FE2002
(drive just snaps into it).
I would suggest using CarbonCopyCloner to “clone” the contents of your existing internal drive to the SSD.
CCC is FREE to download and use for 30 days (this costs you nothing).
Another advantage of the external SSD:
Someday you’re going to get another Mac.
When that day comes, it’s easy to just unplug the SSD and “take it along” with you.