Multiple materials or texture on low poly meshes?

Question

I'm creating low poly environment in blender and importing it to unity. In blender I just have mesh with few materials assigned to different faces. I know two approaches to export it into unity: just export it with materials or render texture and then assign it to the object. My question is: Which option is better in case of performance?

From what I read using multiple materials is worse in case of performance(correct me if I'm wrong), but when i add texture to imported object it still shows that it uses few materials in mesh renderer. Am I importing it wrong or it should be like these?

There are screenshots of mesh renderer before and after I add texture:

Answer 1

Multiple materials are performance killing. But if your game is very tiny, these are not much on an issue. Not suggested anyways.

When exporting with single texture, remember deleting additional materials in blender. Or you can set the value of Size under Materials to 1. That case it will remove the materials keeping the first one or you can set the textured one there and remove others as well.