I won't pretend to understand everything that is being discussed in this thread Bruce, I have no inclination to do so either. However, what I will say is that I read on the P3d forum page, that was a post by one of the devs (Beau?) that P3d was made to run with HT off. Following that advice I did more than a little testing and I can quite categorically say that my system, no body elses, but on my system, it ran definitely smoother than with HT turned on. I also found it best to leave any affinity mask setting vacant from the cfg. Take from my experience what you will.