I use MED to do it. However, MED, as of 6.40.5, is full of limitations, bugs, and annoyances that's still keeping me from doing anything with my 3D project. I do it using calculations and planning (along with some other tools like my mind game, Excel, and Windows calculator).



This graph shows how many polygons are being rendered per seconds with each given polygon count and number of objects (duplicated ones). From 2000 to 5000 is where the peak performance is thus keep your models between 2000 and 5000 polygons each for the most detail and best performance.