Fired up the old 2003 G4 PowerMac to do something about it having 12 separate iPhoto libraries. I used iPhoto Library Manager to consolidate those 12 libraries into a single new one. It contains 1491 photos & took 8 minutes to export the 1.9 GB file to an external CF card via Firewire 400.
I’m copying the same file to my MacBook Prousing Firewire 400 cable connected to a Firewire 400/800 adapter, a Firewire 800/Thunderbolt adapter & a Thunderbolt 3/Thunderbolt 2 adapter. The copy process, according the the Finder will take 27 minutes.