↝ OWC / MacSales.com...
↝ diglloyd B&H Deal Finder...
Buy other stuff at Amazon.com...
Mercury Elite Pro Dock 16TB
Apple iPad Air 3 WiFi+LTE Current Model
192GB memory $1048 Mac Pro save 65% vs Apple!
How to Set the Startup Volume / Startup Drive/Disk
When changing the startup volume, be sure to choose it explicitly or there will be a delay in system booting.
Open, then choose to set the desired drive as the startup drive.
All bootable volumes show up in System Preferences => Startup Disk*.
You might want to also disconnect or remove any older boot drives when making a switch, to avoid confusion (this is why using different names is also a good idea).
* Startup Disk is an error in terminology; it’s a startup volume (a disk can have many bootable volumes). Apple has not fixed this terminology bug in decades.
Tip: you can boot off any bootable volume at system startup by holding down the Option key; a list will be presented. Doing so does not change the default.