In a scenario I am rendering only two cubes one at z = 10 units and other at z = 100 units,

what difference does it make if I set

- Z
_{far}= 500 units - Z
_{far }= 1000 units

Since the depth test will only check for fragments with common Z value and will render the cube at z = 10 units, does any of these Z_{far} values will provide same level of rendering optimization in this case or different ?