Real-time ray tracing, stippling/noise.

There are so many things I don’t understand about ray tracing, especially how to set it up! I have a datasmith imported house model here that I made in Sketchup. I’m trying to light it, so I added a sunsky and I turned on RT. I get nasty stippling/noise which I think may be from global illumination. I’m not too sure which setting I need to change. Can anyone take a glance at my postprocess RT parameters and tell me if there’s anything obviously dumb? (4.25 by the way).