Why do I get two different average round trip times for the exact same pings in Realtime mode and Simulation mode?
In Realtime mode, time is always running regardless of the events occurring in the network. In Simulation mode, time is event driven, under your control. The time in Realtime mode may be affect by the speed of the computer Packet Tracer is running on and the number of devices and protocols running in Packet Tracer. For more information, please view the “Time Management Between Realtime and Simulation Mode” section in the Simulation Mode: Special Notes page.