I know this is a rather old thread, but the topic is not, it seems to me.
Being a new Ardour user (Ardour v7.3.0 on Debian 12), I stumbled upon those names “buffer/ # samples”, “period/ # frames”:
- in the GUI window Audio MIDI setup
- in The Ardour Manual - Audio/MIDI Setup
After longer investigation I concluded:
- “buffer/ # of samples” => “period/ # of frames” as in Jack
- “periods/ # of frames” => “buffer/ # of periods” as in Jack
If I am I right, would you correct these items to name equal to f.i. Jack…
Or, am I missing something?
PS: I m new to the forum, so: Thank you all of Ardour devel team, it is great work you are doing! 
ukisensei