FPS issues with my hardware! Thanks

[killen]

I bought the game few days ago, the game got updated, but i am still having fps issues. My specs are: intel i5-2400, 8 gb of ram and radeon hd 7770 ghz edition... i don't know why, my pc can handle the game even in ultra while playing on quick missions with 8 planes together, but if i go to mp battles, the game start lagging (i think it drops to 30-40 fps, i have not done any tests yet)! why i'm not really happy of my purchase.