Video cards can only work on the data they get. The CPU has to generate the data for the video card. In a balanced system, neither is the bottleneck. However, in a dual-8800 video card arrnagement, the 2.4Ghz CPU is probably the bottleneck in Aces High.
It does not matter how many cores you have, once you get passed 2, for the game. It is the clock rate per instruction that matters the most for the best performance.
Multiple cores do not gain alot of performance for any single application instance. Multiple cores are best suited for running multiple applications at a time. Aces High will, natively, use 2 cores, and that is it. For the 100 cores would run the same as 2 cores, if the clock rates are the same.
In this instance, a 3Ghz E8400 would outperform the Q6600 by a pretty good margin.
Now, if you are running some type of video editing software, such as Sony Vegas Pro, or Adobe Premier Pro, then the Q6600 is a bette choice than a dual-core CPU would be, even at the slower clock rate.
Overall though, Your system does not appear to be running all that well. Is the CPU overheating? If you have Intel Speedstep enabled, and it overheats, it will slow the CPU down. How about your RAM? What speed is it?