"Longer" is a relative thing, of course. If you have a very fast machine, you might not notice the increase for a simple displacement problem. But displacement involves temporarily complicating the mesh, so every calculation should increase in length. I think setting the Displacement Bounds to 1 is excessive, but I don't think high bounds increase render time. Stewer has an excellent FAQ on rendering that gives the recommended setting as 2x the largest Displacement value you have set. In other words, for the default displacement of 0.08... you would use a Bounds of less than 0.20. His discussion of displacement is the classic on the subject, by the way. His explanation of the need to offset your displacement is the key to using it effectively. M