I have a GTX580 1.5mb and it runs smoothly at 1080p at max settings, never had any graphics problems
I don't believe you.
My last card was a GTX580 @ 950MHz and i couldn't run the 4xAA in BF3 without it plummeting in performance to the point it's unplayable.
AA off or 2x and FXAA on was the most i could get.