– you can use Speed as a multiplicative factor for the timescale.
– In the motion equations 1 meter = 1 blender unit. Speed can be used to assign a different measure to a blender unit, so you are not ‘acclerating’ the scene, you are setting a smaller one that will seem to run faster (the period for an ideal simple pendulum depends only on the length L of the string).

Blender Soft Body Simulation Speed