Carrying on from the last post I have found a couple mroe ways to speed up the renders:
1: Looking through the texture files I have found there are a lot of textures that are a huge size and totally unecessary for the scene. I went through and changed each size of the textures and I also had to change any textures that were .JPG or .TGA to .PNG.
2: I also found that if my file textures are too large and I need them to be that size then I can change them to a .MAP file. This file format is memory-mappable, which means that Mental Ray can cut
it up and use only bits and pieces in RAM as they’re needed. Also, it
can flush those parts as soon as they’re done being used. There are a few fiddly ways to do this but thanks to the FileTextureManager script this can be done fairly easy.
3: Instancing my geometry. IIn the scene there are around 100 tents that are very high poly. My mistake was duplicating them without instancing them. This can be done with the Duplicate Special feature. I really don't want to reposition 100 tents again but I guess it will be necessary!
4: Most importantly .... Delete History and Optomize Scene File .... of course.