I tested a small scene like you said and also a few scenes provided from Octane. They are fast and fluid. I was so fixed on the tree that I forgot to test that, sorryDo you have this behavior with any kind of scenes, for example a scene with only one cube or sphere? ... Please, open the Layout, enable Octane and load a cube. Do you have problems moving this cube or the camera while the IPR is rendering, with the display GPU priority set to low?

But why is a (polygon heavy) tree soooo slowing down the ui? Is it because of the many alpha maps that are used for the leafes?
I'll switch the cards to try it out and report back. Could this be a demo thing like with LW and the 3DConnexion Mouse? (which works fine now with the full version of LW)
Cheers
Philipp