I'm running the Steam version of KSP, using 64Bit Linux Mint with the KDE desktop environment, on an i7 laptop with 16GB of RAM and an NVIDIA GPU. I thought for the first while that Steam had automatically installed and was running the 64 Bit, multi-CPU version of KSP. Of course it wasn't, and as I started progressing in the game and adding mods, I started hitting the RAM wall and I knew something was up. Found the solution and my performance went through the roof. No crashes, Graphics are maxed. I'll get to the point: If you are a 64bit Linux user, running KSP in Steam, it is automatically running the 32bit version as it assumes the 64bit version is still too experimental and buggy (which it isn't particularly). So here is how to do it. EDIT: This fix works best for those with NVIDIA graphics cards, but Intel/ATI cards and everyone else you can also benefit, please scroll down to the bottom For people with NVIDIA GPU, You will definitely benefit from the following: 1) First, create a text file in your KSP folder and name it ksp.sh Open ksp.sh in your favourite text editor and add the following script: For Multiple Cores: #!/bin/sh export LC_ALL=C export LD_PRELOAD="libpthread.so.0 libGL.so.1" export __GL_THREADED_OPTIMIZATIONS=1 exec taskset -c 2-3 ./KSP.x86_64 For Single Cores: #!/bin/sh export LC_ALL=C export LD_PRELOAD="libpthread.so.0 libGL.so.1" export __GL_THREADED_OPTIMIZATIONS=1 ./KSP.x86_64 2) Save and exit 3) Right click on ksp.sh and check the make executable box in the permissions tab. OR if your version of linux does not have that functionality, then do it via terminal as follows: As root, open a terminal in your KSP folder and enter the following code: chmod +x ./ksp.sh 4) Now simply double click on ksp.sh to launch KSP whenever you want to play. 5) Blow things up with your new performance! 6) Profit (note: if you use the steam launcher to play, it will revert to 32bit. Always use this ksp.sh shell script to launch KSP!) For NON-NVIDIA users: The simplest way is to just open up Steam, right-click KSP, select Properties, click on Set Launch Options, and enter LC_ALL=C %command%_64 you can then launch the game normally. However, you can still benefit, although not to the same degree by using a shell script. This will run the game without the Steam Overlay and also it will set the processors to the second and third, leaving the 1st processor handling OS and background processes, which will save you a tiny bit of RAM and quite a bit of processor power. 1) First, create a text file in your KSP folder and name it ksp.sh Open ksp.sh in your favourite text editor and add the following script: For Multiple Cores: #!/bin/sh export LC_ALL=C exec taskset -c 2-3 ./KSP.x86_64 For Single Cores: #!/bin/sh export LC_ALL=C ./KSP.x86_64 2) Save and exit 3) Right click on ksp.sh and check the make executable box in the permissions tab. OR if your version of linux does not have that functionality, then do it via terminal as follows: As root, open a terminal in your KSP folder and enter the following code: chmod +x ./ksp.sh 4) Now simply double click on ksp.sh to launch KSP whenever you want to play. (note: if you use the steam launcher to play, it will revert to 32bit. Always use this ksp.sh shell script to launch KSP!) I hope this helps someone!