I didn't notice any improvement at all regarding physics, though I wasn't expecting any. Anyone should feel free to correct my layman's interpretation of physics in KSP: This is not a problem with KSP, rather it is the game engine (Unity) not utilizing hardware resources. The physics calculations done by the game engine are still single threaded, and don't use more than one CPU core, nor does it use the GPU for physics. Because of this, the game will lag horribly with large part counts, even on your beast computer with an i7 and 32GB of RAM plus a 4GB video card and an SSD. Until we get actual threading support from Unity, and/or have physics calculations done by the GPU (which is much better suited for such tasks by many orders of magnitude), we will be living in lag central. Edit: Also, I believe the physics issue has been discussed at length previously, a forum search should yield better and more complete explanations, so long as they weren't eaten last month.