more of a guess but it can make a big, big difrance. the longest a shader that was fake SSS toke on the femail buy its self was about 34 sec, while the pSSSt shader ran it up to 5:00minutes.
If you do anything with finalGather FG or anything like that with occlution in MR you might want to as well stick with the SSS it will not take much longer than like FG will anyway. and the SSS has oclution bilt in to it.

Wandering, tell me aobut the scene and what you want to acomplish visualy with it ?


if you plan on doing a animation I do agree ya have to find good resonable time salutions . the animation on the robotic' horse neck was like 2:10 a fram something like 445 frames. with only FG at 600, where as I latter loaded up a dirtmap shader and it chucked out the frames at 42sec each. and looked better. Had I not finished most of it with FG already I would have switched for sure.