Well if I loaded the whole model in to memory all at once it would.. but I take chunks of the model and work on them as seperate files, so it's fast and easy to work on
It's one of the advantages of the way Lightwave: I can work on the model as a number of components in modeler - and assemble them all together in layout when i need to render.. which is also the downside, because it's a huge hassle keeping track when I keep moving the layers and files round , hence I only like to do it once I have finished a particular 'model' and the layers and positions of the layers are fixed!