DGSketcher wrote:When you save a View of the 3D Window the Cut Plane state is stored in the View. If you then go back to the Floor Plan (without activating a Floor Plan saved View) then the 3D Cutting Planes will be ON in the Floor Plan as well. This might be a cause.
I have just spotted that I have the 3D cutting planes turned on whilst working on a floor plan and there appears to be a significant impact on the screen refresh rate compared to turning the cut planes off.
P.S. I don't know when or how they got turned on for the plan view where I assume they have little use?
Take a look at my video in this link and see if this is the same thing you are experiencing? Every Mac in our office has this happening in AC 18 / Yosemite. This behavior is new and exclusive to Yosemite.