Internal or external SSD would work faster and better?
I have 27" iMac 2017 with an original HD drive, my friend's 27" SSD runs so much faster. Can anyone suggest what to do, install internally, or run as an external drive using Thunderbolt? I watched the MacSales tutorial, and even if it does not look complicated, I would not take a chance to put it inside. I have a clone drive, but I don't want anything to happen to the motherboard.
Thanks.