dual core cpus dont perform well in games at all
It's Intel dual core that sucks at games.
AMD X2 is faster in games than same clock speed single core AMD, especially when user has Antivirus and Firewall running (reviews don't have background apps running).
MAX framerate with 4000 is higher, and even average FPS is higher, but lowest FPS is higher with X2 4200.
Second core makes framerates more stable, there is no "chocking" of CPU when background apps need CPU cycles.
Game levels load faster with dual core CPU.
2006 we have games based on Unreal 3 engine, and it is using multiple threads.
So go for X2.
<font color=red>"We can't solve problems by using the same kind of thinking we used when we created them."
- Albert Einstein</font color=red>