OP : The reason that it is showing you that - is because systemrequirementslab is innacurate, and generally poor at assessing your system.
Go to yougamers and check your system there. I guarantee it will say you have a 6790 1GB.
"Also, does anyone think that running BF3 on high AAx4 AFx16 HBAO maybe worse then running All medium (except for textures) with VSYNC? (In terms of fps)"
Um, to answer generally :- It is highly likely that BF3 on high with all those extras with your card, will run slowly. Certainly below 60 fps. On medium, the game will likely run well, but with vsync on - the framerate will go only as high as your monitor's refresh rate. With vsync off - it is possible for it to go higher than that.
Let me explain: Vsync is to do with your monitors refresh rate and matching that with a 3d applications framerate. Simply, 75hz from your monitor = 75 fps from your rig (with vsync on.) That is an example, it is entirely possible that your card can outperform or underperform that 75fps. It all depends on your systems performance.
Here's another example:
1)My rig can run game A at 100 fps with Vsync off. I turn Vsync on and now game A runs at the same framerate as my monitor. 75hz = 75fps.
2) My rig can run game B at 40fps with Vsync off. I turn Vsync on and the game still runs at 40fps, despite my hz rate being 75.
That is what Vsync means. The idea behind it is to average out your fps to give a better experience between your hardware and your monitor. Not everybody does it or even likes it.