after testing with IDL for more hours its :
-faster

• less artifacts. maybe just a litte but not obvious ones.
  -and faster
  i am happy with IDL now. and i am happy with shadow samples.

poser did crashed in the material room 2 times. but before SR1 it crashed almost all the time. it once also crashed when i changed shadows from RT to DM. i am not good at english so i can nto report those bugs.  if someone else will have the same problems then he should do it. thanks.

but SR1 did change a lot of things on better.