DTS Multi-Subobject ?

Hello ,
I had a question about the Faq on DTS
in the faq it is write

Quote:Are there any issues that I should be aware of if I use a multi/Sub-object material on my model?
In fact there is. Using Multi/Sub-Object materials on your models can affect the performance of the engine. When you have multiple textures on your model, the engine must draw (and keep in memory) an instance of the model for each texture that is applied to it. So if you have 2 textures applied to a node and that node is 500 polygons, the engine will actually have to draw 1000 polygons and keep that data in memory.

I'm not an expert in 3D. the sentence

Quote:Using Multi/Sub-Object materials on your models can affect the performance of the engine

One model is it one file (.Max) exported in dts or one object in the File ?
If I have One cube and one sphere in a file .max not attached not grouped,...
I place One mapping by object, is considered like One model or two model ?

thanks for your response
Elday