My SourceTree GIT manager was freezing for 5-10 seconds when switching between repositories.
These commands fixed the issue:
$ git config --global core.preloadindex true $ git config --global core.fscache true $ git config --global gc.auto 256
Also in combination with adding GIT program folder and SourceTree program folder to excluded paths for Windows Defender (antivirus scanner). The switch between tabs is now instant.