I cannot give you an exact number for the framerate, I don't own the card, and all I have is Crysis Warhead.
I can tell you that it will handle Crysis very well. Don't worry about Crysis.
That card is useless to you. It's the eyefinity6 designed to drive 6 monitors at once. Get the 5850 and a better monitor. It will give you a much more enjoyable experience than a wimpy monitor and a slightly better card.
The 790FX-GD70 will be better for you. I highly doubt you need dual LAN chipsets, and that is its main advantage. Get the GD-70.