Congrats on the purchase! Be prepared to spend a ton of time with it. I've had it since release, and I find something new every time I play it.

As for your system, as mentioned above, the game has a ton of graphic options. The two right off the bat that I would turn down would be MSAA and the Water effects. They are huge power takers. Even the lowest water effect setting looks stunning.

You'll be fine with RAM as I'm running 16gig as well.

Once you get it dialed in, it should look incredible on your machine.

Just be prepared to spend some time with it, because it simply in my book is the greatest game ever produced.