It's not crashing man get used to it. If you want to render such a high setting set it up and walk away. there is another thread here just started that explaines the whole works and what to do about it. It's a thread about rendering big sizes. the first 4 % is the first and second pass the next pass goes from 4% to 25% or even a smaller step i can't remember then the last pass 25% to 100% then the antializing pass and that's going to be about 400 TIMES SLOWER than all previous passes so if it's taken 3 hours say so far the very last pass will take 15 more hours with the counter not updating appearing to be crashed when in fact it's hard at work. Group group and group some more. set it up so objects near each other are in a group. keep doing that forground bacground all the way across till everything is grouped. That will speed it up somewhat. !!!!!