Choose the smallest value possible for the report interval. This provides the most accurate count of concurrent users and, for most users, does not create any performance problems in terms of network traffic or server CPU usage.
If you are not sure what report interval to choose, the following considerations might help you to decide:
At the end of each report interval, the Z and I Emulator for Web server counts all the workstations that have reported. The reports and the CPU resources required to count the number of workstations are very small.