heavy lag on gaming pc

[corwera]

hey there
i have a gaming pc (specs at the bottom) which lags heavily at large battles even at the lowest ingame graphical settings and at the highest power options. to armies is no problem, however when the mongols arrive and i have to fight four armies trying to take my city, then i get a lag so bad that every to seconds skips on 6x normal speed.

all drivers are up to date and running flawlessly. when i open the performance windows (CTRL + SHIFT + ESC) i can see that the pc is only using app 4GB of the RAM and about 12% of CPU capacity. on the writing log on the CPU usage, it seems to go up and down from about 5% to roughly 70% every second or so.
any tips? )

my specs are:
2X HD RADEON 6950
12GB RAM 1600Hz
intel i7 2600k
windows 7 pro
ASUS p8p67 pro mobo
all files regarding the game is installed on SSD.
(if there's anything else you need just tell me).

thank you for your time

[irishron]

Being XP based, the game will use only 4gb of ram including the graphics ram. Short of a rewrite of the hardcode to 64 bit, you will never use the other 8 gb unless you can find a way to dump all your background programs onto the other cores while playing. The game was last updated Feb, 2008, a long time ago in games.
The game is so well "optimized" I would actually expect less when the Mongols and Timurids show up even with a i7.
Being a Total War game, (1)have you the game's profiles installed for crossfire, and (2)have you tried it with just one card?