The Op is right, but not about the reasons. i can give you a hypothetical for you, and it actually would work. write an engine in x64 code. performance problem solved. add 32-bit support with on-rail physics and the current system, have it switch during warp, through a secondary release, compatibility problem solved. run a separate process for on-rail calculations, allow both to be used in tandem, other compatibility problem solved. the enitre reason i want N-body is the challenge. KSP is admittedly boring once you have craft in oort-like orbits around the sun, geosync satellite power relay & transmission net, on all capable planets, 3 different moon bases, multiple outposts on laythe, eve, duna, eeloo, etc. i also want realism, its my biggest enemy, is the main thing i notice is the slight inaccuracies. and i wanted to build a massive lagrange point station. besides that, your points about your computer melting the face of the sun just don't add up. i have a pc capable of 350+ craft building & flying, so i would take a performance hit for n-body. i just fail to see the idea behind the highly inaccurate physics, know what i mean?