SammChisnall :
burdenbound :
Just a heads up, the ARMA games perform poorly in multiplayer regardless of CPU. So don't get bummed out when those don't work very well.
Not true for all CPU's, high end i5's and i7's can run ArmA games on max settings 60fps. I agree that they are very poorly optimised with a tragic engine but they are still playable with Intel CPU's. My recommendation, stay away from AMD if you are planning on playing ArmA
From personal experience with an i5 (rig in signature) and numerous posts online it really depends on the server. Single player mode it's not as much of a problem but for most multiplayer servers the CPU doesn't get utilized like it's supposed to. You will find that the CPU and GPU are not working at full load and FPS are low. Think it has something to do with too many objects being rendered server side or something. What ever the reason performance is not very good.
If you have tweaked some settings to get it to work better I would be interested in what you have done.