I got some performance result with my script converted in Cython ( C language ). My gain is about 20times faster with heavy simulation ( like 64k particles and more ). It’s a good gain , a simulation with 128K particles take 4-5days with my old python script and can take 4-5hours with my new one. And I have place to optimize again. Not stable for now so I need to work on it before a release but it’s going on the right way for now !