The SET VPC_SAMPLING Collector command enables the collection of PC values for random vector instructions and causes the sampling rate to be applied to the wall clock. The collected data lets you determine the scalar/vector parallelism throughout your entire program. When you collect vector PC samples, the sampling interval timer includes all idle time associated with the current run of the program. This form of sampling shows you where the time is being spent in the program with little cost to the time of actually running the program. time. You can set the time interval by using the /INTERVAL qualifier.