It the future, please don't double (or triple!) post.
Anyway, as for your question, unfortunately game lag is very common for civ 5, even with very high-end computers. I have a HP laptop with an archaic video card (even though it isn't even a year old, HP laptops are just absolutely terrible) so I have to go to strategic view and the maximum size I can have is small/medium. Unfortunately, if your game is lagging, especially if you have a laptop, there is little to nothing you can do to speed up the game, other than playing on smaller maps, switching to the (incredibly buggy) strategic view, defragmenting your computer, or, and I know that this is out of the question for most, get a new computer.