How to run simulation faster than real time with multi uavs in gazebo?

Hi, I want to know how to run simulation faster than real time when using multi UAVs in gazebo. I have set PX4_SIM_SPEED_FACTOR and the real_time_factor and real_time_update_rate in world file. And then ‘roslaunch px4 multi_uav_mavros_sitl.launch’. It doesn’t work and error occur: Service call failed: transport error completing service call: unable to receive data from sender, check sender’s logs for details. Is there anyone knowing how to do?