Also, this is why often, when doing the"modelling" (building) part of the work, with l;arger models it's better to turn textures off completely. If you are in monochrome model, at least you can see what's front and what's back face. This (and a couple of other tricks like turning off shadows or "hide the rest of the model" while working on a detailed component) can speed up work even with a slower computer.
