In another location some ROS / Gazebo users have been discussing whether a graphics adapter will improve the execution speed by using the GPUs. The discussion recognizes that the real-time factor will increase because the graphics will render more quickly. Also, that the GPU is used for image sensor processing.
The basic question is if in simulated time a task takes 10 seconds will adding GPUs improve on that simulated time, e.g. take 8 seconds for the same task.