Oliversisu :
Okay, i have no idea how i overclock but i will try searh on it. Thanks for you help.
If you're still reading this thread and haven't figured out your problem, see if this helps a bit.
To begin, ArmA is not optimized well at all. It won't utilize your CPUs full potential no matter what processor you have. But it will run better on a higher clock then it will on a lower one. This is because of the ai on the map, hundreds at a time. Se a duel core at 3.8ghz will do better than a quad at 3.0. So just consider that, and even a mild overclock might cause you to get better fps.
On the subject of altis life, I play that as well and its a whole different problem. Then main reason for lag however is that there are about 200 AI on a map that is 300 sq km. And every time one of these AI are accessed, a menu opens and the server has to process that. You can also count all the activities you do as another AI, gathering grapes, making moonshine, and selling it for instance are another three AI. So imagine playing on one server with 500 people. That's basically what's happening in altis life and the servers just can't keep up, as mentioned above.