KSP Not using all of my computers power.

[cool beluga fish]

So lately I've been getting really horrible frames with ships that have over 100 parts and I discovered that KSP is only using about 30% of my CPU. I have a GTX 1080 an i7 7700k Kaby Lake, and 16gb kit of ram. I have V Sync turned off and the frame limit capped off at 180 frames. And I know that it isn't because of thermal throttling because my CPU doesn't go over 55 Celsius
and because I've played more resource intensive games without a problem. If anyone can help that would be great because i'm really tired of launching rockets with 20 frames.

[Chibbity]

KSP (like pretty much every video game.) can only run it's physics on a single thread. It has a lot of physics to run as well. It can use 2 threads, but only for two seperate ships near each other.

It's only using 30% of your CPU because it can only use 1 or 2 of your 8 cores at a time.

You are mistaking one resource for another. The other games you played were very GPU heavy, this game is very CPU heavy, more specifically; single core performance in particular.

You can turn up "Max physics delta time" in the game options to help with high part count ships. Setting the KSP.exe process to run on high priority couldn't hurt either. Use the 64-bit version obviously.

[Astronaut]

Are you using all of ksp's power? make sure you're running 64 bit. at the main menu in the bottom right corner it will say (example) windows player x 32. that indicates you're running 32 bit, you might want 64 if you son't have it already.

[CalmLlama]

I have an I7 6800K and i have a similar result with CPU usage. Its not about KSP not using enough CPU%, its about how much of the overall resources can your computer contribute to KSP. KSP runs much better, for example, off of my M.2 than my mechanical.

[robertordf]

make sure that you are using x64 version, its a common bug. I run 500+ parts on my i7 with more than 30 fps with physics on max

[flying diomedea]

Unfortunately multicore CPU can be efficiently used only by an OS able to balance load assigning threads dynamically; e.g. a server answering some hundred requests at a time, each request being managed in a separate thread. Most programs have one master thread doing the bulk of all computations, Unity/KSP is no exception. Since Unity 5, multithreading allows to split load when different objects physics are managed; but KSP isn't likely to have situations where 4/8 objects are off-rails at the same time so to evenly load all CPU cores. On the other hand, Unity PhysX library deals heavily with a nVidia GPU, so the bulk of repetitive calculations is actually performed in parallel by the GPU instead of sequentially by CPU cores. On my system, of course the single CPU core dealing with the master KSP thread remains the bottleneck, but generally GPU takes a good 90% of load at all times to relieve it. Besides Unity, a great deal of coroutines are run within KSP code, and those are multi-threadable too. However there are limits: I was involved in a add-on project for KSP that would greatly benefit from multithreading, but passing data around with multithreaded calls was taking more CPU time than doing in one thread.
About the poor performance, let be known that what said for KSP holds true with any add-ons too: they all depend on execution of the same single master thread, but unfortunately each add-on adds more load (operations to be performed each frame), in particular when the add-on is required to display/update more information instead of silently doing in background.
As others often say, is true that KSP runs better the more the CPU clock frequency. Number of cores helps little, cache size only marginally do. Therefore is very possible to observe a older machine with an obsolete, but fast CPU, outperform more modern computers when running KSP.
KSP is very different than most other games: it performs an enormous amount of operations each frame to keep track of some very detailed physics in game; other games deal with a much simpler physics model, but tons of graphics effects that however remain with the GPU to create.

[Astronaut]

Originally posted by robertordf:

make sure that you are using x64 version, its a common bug. I run 500+ parts on my i7 with more than 30 fps with physics on max

I run 64 bit, around 60 mods, 1.1.3, and I still crash ocasioncally but the crashing is worth it( and the game takes 15 minutes to load)