How are changes detected? Understanding performance over SMB

I am trying to better understand the performance of a kopia snapshot running against a samba share. How does kopia detect changes on a samba (NTFS) share? How does the maximum parallel file reads affect that?

I am using KopiaUI running on a Windows 11 machine. The repo is a disk pool on the Windows 11 machine.

I am asking because, however it’s reading the directory structure and checking for changes during the snapshot is causing the CPU usage for the client connection to my NAS to get maxed out.