I get about 30fps(measured by fraps) using the recommended settings by the game which are standart but once every 10sec they drop to 0fps making it unplayable. Had this issue in arma 2 but every other game(crysis 2, farcry etc) just plays smoothly with high settings.

A video for easier understanding of the problem:
http://www.youtube.com/watch?v=pLaoC3A1PD4&feature=youtu.be

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