Optimal way of incremental backup thru 60 mbits link on Windows Storage Server

Hi! I’ve been using urbackup for some years now with nice results overall. I’m encountering an strange situation in one implementation that results in really poor performance.
Server side is Windows Storage Server 2016 with plenty of resources available. Urbackup storage is on a separate volume.
Problematic clients are Windows Storage Server 2016 based with lots of small files, like 1.5 millions PDF and so on.
Link speed between client and server is almost every time limited to 60 mbps.

How can I improve backup speeds ? Its seems that it takes forever to index files and make hashes, I’ve setup raw for backup type to disable that, but is not working.

Any thoughts ?

My first thought would be - Are you using internet mode or backing up over the LAN. If using internet mode, you will be limited by both the servers upload speed and your download speed. If using LAN mode, I might suggest deleting the client from the GUI and uninstalling the client, then reinstall the client without creating a new client in the GUI. Then add the ip address of the client to the add client window and see what happens. I have found this to produe the fasted LAN speeds.