The amount of RAM needed depends on several factors: Multilight: Each separate light slider needs to be stored in RAM so the more separate sliders you have, the more RAM is needed. To minimize the RAM usage you can apply the same emitter material to several geometry objects that are meant to be emitters or use the Multilight groups in which case they will all use the same slider - saving RAM. Color Multilight will need more RAM than regular ML because each color channel per light also needs to be stored in RAM.
Pretesselated displacement: This type of displacement subdivides the geometry before rendering (unlike On-the-Fly displacement), which renders fast but needs to hold the extra geometry in RAM. The higher the subdivision setting in the displacement material, the more RAM is needed.
Extra render channels: The extra channels you can specify in the render options (Alpha, MatID, ObjectID, Normals etc) will need extra RAM to render. The amount they need depends also on the resolution of the main render.
Taking into account all these factors it is impossible to say how much RAM you will need for a certain render. It is best to test a render on your machine and check the RAM usage during the render.
|