If you are creating your level out of models or importing a level from fbx, group small meshes together to form meshes around 1000 polygons. This makes a major impact on performance, my level went from 30 fps to 180 fps.
An easy way to do this is to use the mesh size modifier in map properties if you are compiling your level with the map compiler. Does anyone know exactly how this works? Does it combine all meshes into groups of 1000 polygons or only meshes that exceed 1000 polygons? I've had to manually group meshes by ctrl-g then selecting the single mesh option.
