Input Simulation for PowerPlay, how long?

Hi everyone,

Can you help me please,

Does anyone here know, how long simulation time needed to achieve ideal power consumption simulation/calculation. I have FPGA design here, and I have tried simulate power consumption using PowerPlay using two different input time simulation. First one I used 10 us of timing simulation resulting 351 mW power consumption, second one 200 us same simulation resulting 354 mW. All resulting High Power Estimation Confidence. But that wasn't far difference.

So how long the ideal simulation time to achieve ideal power consumption simulation?

Thanks... :)