Since bigger is better, I usually want to play on Huge worlds with max number of Civs and City States. After I begin conquering the world and my empire spans about 50 cities, the game begins to crash. The crash usually occurs when I hit "Next turn", but it has also happened when giving unit orders etc.

The crash doesn't happen if I play on "strategic view" where the graphics are much simpler.

I have tried re-installing the game and updated graphics drivers. Otherwise, my computer is powerful enough to play Battlefield 3 and Skyrim on max settings.
Any ideas on how to fix this?
