When you use the Active Directory Sites and Services administrative tool, the Active Directory replication schedule relies on a registry entry to schedule the replication of pending changes.
The default replication schedule for domain controller changes is 5 minutes, and it occurs every hour, when no changes are pending, to allow the Knowledge Consistency Checker to verify that the replication partner is available and working. Once notification occurs, notification is paused for 30 seconds, to prevent simultaneous replies by replication partners.
You can modify these defaults by using Regedt32 to navigate to:
To modify the delay between the change to the Active Directory and first replication partner notification,
double-click Replicator notify pause after modify (secs). Change the Radix in the DWORD Editor to Decimal to see the default 300 seconds (5 minutes). Change it to the number of seconds you desire.
To modify the notification delay between domain controllers,
double-click Replicator notify pause between DSAs (secs). Change the Radix in the DWORD Editor to Decimal to see and change the default 30 seconds.