HI. Actually, you can lower the number of stars that are displayed with either the 1 million or 2 million stars.dat. Lowering the # of stars displayed will boost your computer speed significantly. You can do it two ways.
1. Either drag the slider in the render menu from 1 million LY to something less, or
2. Press [Ctrl { ] to lower magnitude. I find a magnitude of between 9 and 10 is ideal. It shows LOTS of stars but does not slow down my system too much.
Frank