How long should first sync take?

How long should my first sync to an iPad take? I’m syncing via DropBox

I realize that it depends on the size of the database. This database is about 20GB. I don’t want to transfer all of the documents themselves, just the index.

Even so, it seems to take hours and hours. Also, can it be done in the background, or does the iPad have to be active (not sleeping) with the app active?

It is impossible to answer this question.

  1. 20GB is not a small amount of data.
  2. Even wanting to use a shallow sync, the metadata may still be considerable. Remember, the full text of documents is part of the metadata and that has weight.
  3. We have no control over the speed of any remote service. Poor network quality, the responsiveness / reachability of the servers, and bandwidth throttling measured used by the services all affect sync speed.
  4. The mobile device should be on and DEVONthink To Go awake and frontmost during the initial import. The Background App Refresh option is controlled entirely by iOS and only allows approximately a 30 second window, when it allows it to happen. This means we can’t control if, when, or how long it happens. Subsequent syncs are faster since there’s less data being transferred.

Initial, full syncs have taken me hours. To the extent, in fact, that I have set up my iPad with 10-hour-long YouTube videos playing in multitasking to make sure that it wasn’t going to go to sleep while it happened. (I don’t think syncing can continue in the background after a certain point on iOS!)