I've been digging into it all night, (no formal mentions from devs or anyone at Squad withstanding) but it appears that they are using the standard Physx engine that comes with Unity. I'm a developer, and while they may have begun rolling their own multi-threaded implementation, it's doubtful. Physics is a very math / logic (when it comes to multithreaded) implementations. Ask anyone who has ever made a game engine from scratch, and they will tell you the physics part -- the part that makes the game act like real life -- is the most complex part, especially if you need to make it fast. That being said, the physics aspect is what determines whether your space ship blows up or lands, how far the ship goes down on its landing struts, and how fast you can go. Because the current implementation in the Unity engine, it can only do calculations in one core. This technology is antiquated at this point, but as the Unity Engine is used by hundreds -- if not thousands of games -- that don't need super fast math done ... it is probably very low on Unity's todo list. Now, I bet Squad could pay a hefty sum of money and make it happen -- or even do it in house -- but lets face it, there is a game to finish! However, if someone is already doing all the work, and they only need to pay a small sum of money, then hey, we all benefit. What are the benefits? Well, for one, no more 15 minute realtime but 3 minute game time launches... and more importantly, a higher part count before hitting unbearable lag. If this guy's implementation is really 2.5x faster, then we could be looking at 2.5xish more parts ... meaning bigger ships, bases and stations.