Vertex buffer(s)

Hi forum!

While reversing one program, I found that it uses separate vertex buffers in combination with index buffer:

• vb0 = Positions (always used)
• vb1 = Normals (always used)
• vb2 = UV (used only in high quality)
• Index buffer

The only explanation I have: for some conditions (like don’t use UV), they simply don’t pass one of the buffer to the shader.

So, in low quality, GPU memory usage is lower.

Questions:

1. Is there any benefit of separation positions and normals, if they are used in all circumstances?
2. If all buffers are used in a shader, are there any benefits of using several buffers instead of one, that contains all data for one vertex?

Thanks in advance!