Reference Server is used for Stress Testing and runs just 1 virtual user (reference user). This user represents an outside visitor that will examine device availability during the test. Since the server runs only one user there is no significant CPU load. This excludes the Reference Server hardware impact on task execution and session duration. You can use the reference data while test results interpreting.
Also, in the case of the Web Application and Web Page tasks, we will shoot video of task executions for that reference user in the way it appears via a user interface for an outside visitor. You can later use it for further review and analysis.