Mac Pro 4,1 - 48GB Ram - Xeon 3,6 GHz 6 core - Nvidia 680 2GB - 2x 256GB SSD - 2x 2TB HDD

Mac Pro 4,1 - 48GB Ram - Xeon 3,6 GHz 6 core - <a class='btn-link text-dark' href='/search/label/gpu?max-results=12' target='_blank'>Nvidia</a> 680 2GB - 2x 256GB SSD - 2x 2TB HDD

Got it for free! It did not boot, only with the Questionmark folder. And now the main question is, which MacOS should i install? And which runs best on a machine like this?

Author: @InMyGradeHouse