Default is in Windows Server (from version 2008) an option to monitor the performance of Active Directory. De Active Directory Diagnostics. This is part of the Data Collector Sets.
Using the tool, you can obtain very useful insights into the user requires the most CPU load on your DC, which queries are fired, how large replication files were, LDAP how many sessions there were at the time of the measurement, and so on.
These can start at any domain controller using Server Manager | Diagnostics | Performance | Data Collector Set | System. Via a right mouse click you start monitoring.
for 5 minutes he will collect data and generate a report.
in 5 The report was made minutes. You can find it under the Server Manager | Diagnostics | Performance | Reports | System | Active Directory Diagnostics.
It is good to know that the reports are snapshots, and only apply for the domain controller where it was created on raport. It therefore gives a complete picture, but a good indication.