The issue is that both processors are trying to operate, despite that the game can only make use of one. So the solution is simple - disable one of the processors for the game.
There are several methods to deal with it.
1)Change the processor affinity after the game has been launched.
a) After you start the game, minimize it and access the task manager. Right click on the RomeTW.exe process, in the process tab, and select affinity. Uncheck one of the processors.
or
b) Launch a .bat file after the game has been started, to automatically set the affinity. I can make you one if you wish.
2) Use a program\shortcut switch to automatically set affinity upon launch.
a) A simple program such as this can automatically set the affinity if you edit the shortcut target correspondingly.
http://www.kalme.de/index.php?option...d=44&Itemid=35