@fast, your I7 is no where near outdated for gaming. I would honestly either upgrade the video card to an amd 6970 or a gtx 570/80 for top performance. Even a 5800 series card should run this game at medium to high settings fine.
The thing that will kill your frame rate the most is the anti-laising. What that does is that it takes your graphics you have and renders it up to 4x a single second. So imagine four monitors running at one time, then it takes that and slightly bumps each image next to each other to smooth out hard edges. So when your playing you are actually rendering up to 4 game shots at once before you even see the next frame. Even top of the line rigs like mine gets killed by this when there is some vegetation and what not all over the screen. Basically, if everything is looking blocky, then run anti-laising, it also may help you see some opponents better when standing next to a wall or vegetation but you really don't need it in a game. This is where having dual video cards help. One card can render frames non stop while the other keeps the frame rate from dropping.
It's only eye candy. Wont help you out and in most cases is worse for gaming. I recommend leaving it at one or off completely. Vegetation, keep it at medium and also the ground cover. Buildings and models I always render high because it's easier to tell when someone is standing next to a corner. While shadows are personal touch to be honest. I don't like light colored shadows as my own eyes tend to look at the blotches rather funny but some people are not bothered by it at all. I always run shadows high but they are the worse for low end video cards. I recommend low-medium. In most cases when at medium you really don't see a difference from low. A single gtx 580 running this game at 60-80 fps while running at ultra settings is great. Plus being beta it's only going to get better for the updates. So you don't really need dual cards unless your running something bigger than a 42" screen or dual monitors. Then it helps a bit. Remember, if someone is playing on a smaller screen than you, they tend to get much faster frame rates. I use a 46" vizio for my games, it's actually way to big but don't want to buy a smaller screen and spend the extra money so I play it. But someone playing say a 22-32" screen is always going to be faster than me as my graphics cards have to run harder to render the video. Plus not a huge difference between 1080p and say 1680p. That helps a lot as well. I play 1080P all day. I'm sure if I did a fps test on my 26" test rig I would get much faster gaming rates but I like to post with this rig as it's made for gaming. Gives me more of a edge to tell everyone how it really performs.
I'm curious if I should purchase another 560 ti and sli them, or just sell off my 560 ti and purchase a 580. I know I'll have more power with a 560ti SLI setup, but less room for upgrades.
Of course, with kepler arriving sometime next year, I keep ending up back on the 560 ti as I will so be able to purchase a top tier 600 series sometime next year for the same price I'm willing to drop on a 580 right now.
ps-My kick ass wife is helping me get a 580 or 560 for our 3 year anniversary. Haha.