Moving folders · How moving folders works
What does "fast drive" mean in Storage Studio?
Short answer: The fast drive is the external drive — usually an SSD — you picked during setup, where Storage Studio puts moved folders and apps. Move to fast drive, Eject fast drive and similar buttons all refer to that drive.
"Fast drive" is the external drive you chose in Storage Studio's setup — usually an SSD — where moved folders and apps live. Buttons like Move to fast drive and Eject fast drive all refer to that one drive.
It's called fast because it's meant to be quick enough to open moved files directly from it, so things still feel normal after a move. You can change which drive it is from the Drive selector.
See external drives for choosing and setting up the drive.