I used to play civ4 on my old 2008 Macbook black on lowest settings, and still enjoyed the crap out of the game. I recently purchased a new iMac with:
3.1 GHz Intel Core i5
12 GB 1333 MHz DDR3 RAM
AMD Radeon HD 6970M 2048 MB
Mac OS X Lion 10.7.2
I was super stoked to play civ4 BTS on high settings, however regardless of what settings I'm on, the game runs smoothly at first, but after a couple minutes playing always seems to randomly suffer a severe drop in framerate down to like 10fps and lags horribly. I've tried monkeying with the graphics settings to no avail, any help would be much appreciated.
3.1 GHz Intel Core i5
12 GB 1333 MHz DDR3 RAM
AMD Radeon HD 6970M 2048 MB
Mac OS X Lion 10.7.2
I was super stoked to play civ4 BTS on high settings, however regardless of what settings I'm on, the game runs smoothly at first, but after a couple minutes playing always seems to randomly suffer a severe drop in framerate down to like 10fps and lags horribly. I've tried monkeying with the graphics settings to no avail, any help would be much appreciated.
but first things first, do other games run well on your new computer? This would be helpful because then we can tell if it is your game or your computer 
