Unity 5.2.... optimized UI.... coming NOWISH.

[TheTom]

In this case, the single busy thread is likely the PhysX thread, but I don't know that for sure.

Hint: it is not. It is the UI and - the resource system (for in game resources). And that could easily be split into separate threads with a different API. It is inefficient as hell and it is single threaded. What about having all components register their demants and supplies, then resolve them for each resource separately Or, even better, so run the resource allocation in well written code (which it is not) separately WHILE the physics is looping. Yes, you may not get a 6 core machine utilized, but you would use a lot more than one core. Separate the calculation of the heat (another large subsystem) and the drag into separate threads, all running at the same time, then re-synchronize. And not all the calculations MUST run every frame.... heat for example can easily be done a LITTLE slower (every second frame), giving time to handle some other things in every other thread (like calculating things like the efficiency of solar panels). But there are quite a lot of separate subsystems doing time consuming tasks in KSP that can be done in parallel.

Everyone assumes it is physx being slow - it is not, which is prooven by bug reports and measurements. And the history - once upon a time - on the same unity version - physics supposedly was running a lot faster. I could launch 300-400 part rockets, now I get a slideshow. Nothing in physics has changed. But resources was rewritten (bug report about the tremendous impact of bad code earlier in the thread), heat is a lot more complex now and the whole aerodynamics is not for free either.

Seeking items to parallelism is not trivial, particularly when you have to deal with cardinality requirements. But it is mostly doable. By recutting the problem. In case of KSP I could easily split that quite a lot.

Edited September 11, 2015 by TheTom