Message encryption is CPU intensive; more so for the QoPs that use stronger encryption keys. Depending on the application, the type of session, and the workload, message encryption may adversely impact system performance.
For tactical workloads, there will be negligible performance impact when message encryption is enabled.
For bulk data movement workloads such as Load, Export, Archive, Restore, etc., there may be significantly higher performance impact on throughput, elapsed time to complete the job, and CPU utilization.
However, the higher impact due to CPU utilization will likely be more pronounced on the Client ETL and/or BAR server, which typically has less CPU capacity than the Teradata Vantage server.