During the Unicode conversion the system copy causes a high CPU load time during the exports. As most of the CPU power is spent on the data conversion, especially on processing cluster tables.
To Avoid these bottlenecks, it is better to distribute the data among several machines. The system copy tool DISTMON ( Distribution Monitor ) is designed to take advantage of the additional hardware for the database export/import job.
To Learn more about the Distribution Monitor refer the OSS Note. 855772.
Here is the documentation on Distribution Monitor User Guide.