Apache Subversion introduced new FSFS repository format:

• https://subversion.apache.org/docs/release-notes/1.9.html

We've noticed performance degradation (about two times slower) when a repository is updated to the latest format and the bundled SVNKit via file:// protocol is used. Calling 'svnadmin pack' does not improve the situation.

Issue reported to TMateSoft:https://issues.tmatesoft.com/issue/SVNKIT-667