The SSD will occupy the space that the old disk uses. The reason is that if you just leave the old hard disk in the current position and install the SSD in the SuperDrive slot, there will be problems when your Mac wakes from sleep, as it doesn’t expect the SuperDrive slot will be the main drive.
I just bought a Mac Mini off ebay it was upgraded to 8 GB DDR3 but is still a little sluggish. It was suggested to me to install a SSD. I have a few questions if you could answer:
1. When I shop for a SSD how do I know it is compatible? (A1347)
2. Am I going to be able to run the SSD as my main HD and keep the SATA for extra storage or will I need to remove the SATA?
3. I did not get an OS disc since I bought a refurbished unit, how am I going to be able to move my files/os to the new HD? Can I create an image from my existing install or would I be forced to buy the OS? (forgive my ignorance, long time iOS user and used some macs in school but first ever mac I've owned)
Mac mini, macOS High Sierra (10.13.3), 320 GB HDD, 8 GB DDR3 (upgraded)