i7 975 asus gtx 670 6gb ram win 7 ultumate 64bit game installed on crucial m4 SSD 128gb game fluctuates between 80 fps down to 0 , literally making the game look like it freezes every 2 seconds, only running dayz mod does it do this vanilla arma runs fine, its never done it in the past ( i had to reformat about 2 weeks ago ) and just last night i reinstalled the game and mod , ive tried reinstalling mod and multiple servers and it hasnt helped.. any idea what could cause this?