Apparently no speed increase came out of it for mining and it can be even slower, as per Epsylon3:
yes... sm_61 is an emulation of sm_60 P100 fp16 stuff, and when used (look like it is sometimes) its slower than normal ops generated for sm_5x ... So nothing changed for the GTX (and mining cards) about that since CUDA 8
Man, thats a bummer. I read the title for this post and got all excited haha. Hopefully we will see SOME increase... once its released to the public.