Thank you very much for your responses.

I tried some renderings.
FireFly worked for a small picture 12.5x10 inches without ray tracing, and one victoria.
However, when I tried the small picture 12.5x10 inches with ray tracing, and two victoria, FireFly froze when rendering shadow map.

I used Grace Lion Hair by Quaker, not heavy P5 hair.

FireFly does work for a small file.
The fact is that FireFly render is worse with SR3 for my situation.
P4 rendering is working fine.
I may have to remove SR3 ???

Thanks again,
HimiCo.