You log into a dedicated server with only a 20ms ping, there is only 8 other players on and the game plays fine, you can run around, shoot, engage the enemy.
You log into that same dedicated server with same ping and now there is 20 other players, soon as the chopper ride from the side seat view it starts eating up your processor, then when you land and grenades start going off your FPS drops drasticly, you start skipping about, can't even see the bullets or keep track of team mates. Get close enough to a fort to see the enemy you are graphically lagging so bad you can't even lift your weapon to fire on them before they decide to put out thier smoke, set their coffee down, joke about your laggy predicment before they shoot you. I know this only ALPHA, but its a serious issue as this kind of performance greatly hinders people from fully testing out sections of the game like combat with more then 10 people in it. I've tried setting my settings to the bare min, turning off every feature I could and it still lagged with more then 10 other players in combat so bad it was unplayable.

System Specs:
AMD Phenom II X4 840 Processor 3.20ghz
8.00 GB Ram
64-bit Win 7
AMD Rhadeon HD 6800