Working on a HUGE model

Several earlier suggestions might make the model more manageable, particularly replacing over-detailed geometry with textures, and working in monochrome mode. And if you have used components imported from the 3D Warehouse, they are often grossly over-detailed.

One other thing that will help is to use layers to turn off all components or groups that aren’t needed while you are modelling.

Working with Scott Baker (@NewThinking2) on a model about half your file size, we found that using layers to suppress the display of objects not needed while drawing helped very considerably.

Simplifying components also helped reduce the edge and face count dramatically. See for example this thread

Even on a very fast machine, a Sketchup file of this size will be slow to load, orbit, and edit, but it can be speeded up using any or all of these techniques.

See also