Longer explanation of sync_time option.

config/gitlab.yml.example

@@ -135,9 +135,12 @@ production: &base
     bind_dn: '_the_full_dn_of_the_user_you_will_bind_with'
     password: '_the_password_of_the_bind_user'
 
-    # This setting is used to change how often LDAP group membership is updated.
-    # WARNING! Be advised that changing this setting can have severe performance consequences!
-    # Default: 1 hour.
+    # This setting controls the amount of time between LDAP permission checks for each user.
+    # After this time has expired for a given user, their next interaction with GitLab (a click in the web UI, a git pull etc.) will be slower because the LDAP permission check is being performed.
+    # How much slower depends on your LDAP setup, but it is not uncommon for this check to add seconds of waiting time.
+    # The default value is to have a 'slow click' once every 3600 seconds, i.e. once per hour.
+    #
+    # Warning: if you set this value too low, every click in GitLab will be a 'slow click' for all of your LDAP users.
     # sync_time: 3600
 
     # If allow_username_or_email_login is enabled, GitLab will ignore everything