I used gravsim to simulate 1600 massless object and i do it well with just a core of my laptop. I will speak with my supervisor to understand how is it possible to write such a code. Thanks a lot for your help,is very welcome and necessary
First, What is the programming language of gravsim? Is it possible to have a copy of the code?
Yes, is it possible to eliminate the interface and the graphics. The only thing that is important is the output and the possibility to print data files with which to plot orbital parameters, position, velocity....
So i can use such files to make a movie of the simulation with snapshot that i can take from the data files and run it for a million of years in a cluster or in a single core for many days and save the results in a file and plot them later. This is very important because now i can't see any output with the command: output or systematic output

(i stop the simulation, click on output file create data file, create copy, set the condition). I do not understand if i must play the simulation for the time that i use in 'maximum data samples' or if the program do the file for my also if the simulation is stopped.