Although Change Tracking has been optimized to minimize the performance overhead on DML operations, it is important to know that there are some performance overhead and space requirements within the application databases when implementing Change Tracking.
The performance overhead associated with using Change Tracking on a table is similar to the index maintenance overhead incurred for insert, update, and delete operations. For each row changed by a DML operation, a row is added to the internal Change Tracking table. The amount of overhead incurred depends on various factors, such as
The number of primary key columns