I just tried using Direct X 12 and was unable to continue because of crashes. One thing I did notice was that when I used a popout window there was no frame rate loss. Right now my frame rates go from 35 to 18 when using Direct X 11 so I don’t use popouts.
I don’t know if Direct X 12 will be fixed in su 10 but if it is that would solve a big problem for me and perhaps others as well.
It not really in production mode in SU9, its there so you can try it. While there will be improvements in SU 10, it was always slated for the end of the year for “full support”