Alex Pankratov :
Apr 28, 2014Backups can be run in parallel, there's a setting in Preferences ("concurrent backups").
Within each backup files are processed one by one, but all I/O is fully asynchronous (i.e. it can be reading several blocks and writing several other blocks at the same time).
Processing multiple *files* in the scope of a single backup in parallel doesn't really make much sense. At best, it will be as fast as running them one by one. At worst, it will thrash the disk and the overall performance will be worse.
Parallel file copying is now available as a tech demo, see here -