http://docwiki.unity3d.com/index.php?n= ... erformance
Vertex-Lit shaders in Forward rendering path are always cheaper than Pixel-Lit shaders. These shaders work by calculating lighting based on the mesh vertices, using all lights at once. Because of this, no matter how many lights are shining on the object, it will only have to be drawn once. - вот это прикольно
Remember that lights can be forced into a pixel ("important") or vertex/SH ("not important") mode. Any vertex lights shining on a Pixel-Lit shader will be calculated based on the object's vertices or whole object, and will not add to the rendering cost or visual effects that are associated with pixel lights. - вот это тоже очень прикольно