Multi-Sub materials and speed

[Mikhalenko]

Hello,
I just wonder if number of materials in multisub material affect render speed? For example, I have big architecture project and all materials for this bulding in one multi-sub material (50 materials) will make start of the render and render time slower? or better apply each material separately or with not such enormous submaterials? Same question not only for Vray but also for Corona

[hermit.crab]

There shouldn't be a difference, though I tested it with a far simpler scene. You may test it on your scene if you are interested.