Hier mal ein Auszug von http://hewiki.heroengine.com/wiki/Creating_characters:
More characters visible is, in a simplistic sense, good. But there is a price to pay for this: the more you want, the less detailed and unique they can be. This is because consumer video cards--and PCs in general--have strict resource limitations. Properly authored and coded, a modern video card can draw hundreds of identical characters very quickly. But what if each character is a different mesh and a different texture? Or worse, a bunch of meshes and textures each? How many can it draw at a good frame rate then? Not as many as one might hope. Also, remember that characters are never the only things visible in a scene: you'll also have the world being rendered, any mirrors visible, and particles; not to mention the overhead of audio and any post-processing effects going on.
Quelle: http://hewiki.heroengine.com/wiki/Creating_characters