Why are all of my Virtual Users active from the start of a test when using a Warm up time in a Queuing Workload?
This is due to state a "Virtual Users" is in during the warm up period. For example, during the warm up period Virtual Users are considered to be in an active state (i.e. executing, wait DB, document downloading, and thinktime).
This means that all users are considered as ACTIVE Users from the moment the loadtest kicks off (due to the warm up time inclusion)
Where as, in the workload which has no warm up time the users are only considered active in an queuing workload test as they are added to the load over time.
Active Users - No Warm Up Time
Active Users - Warm Up Time
For more information about User States see: