"sailor_ed means that the effect has an impact on rendering time" Even if he did mean that, it's clearly not what he said. If he meant that he would have said: "The results are subtle but definately have an impact. (on the amount of rendering time)" rather than: The results are subtle but definately have an impact. (Visually) If he did mean rendering time then what he said makes even less sense. What he said was that the results will look different, not take longer to produce. No sailor_ed, I'm afraid you are not communicating very well at all but we won't hold it against you.