Mate, do yourself a favour and just give it up.
Why on earth you would want to spend a single penny so you can play the same game before only better looking is a mystery to me.
It won't change the game. If you liked the game then awesome, play through it again or something. I mean, it's far from being ugly (it's actually rather beautiful).
If you didn't like the game before like me then no matter how much perfume you pour over it it'll still be a pig.
There are many rumoured reasons that DX11 was not in it from the start. The main one is probably that the game needs hardware that doesn't exist to run smoothly with all of the DX11 stuff on.
When Bethesda released Fallout 3 they had a HD texture pack that made it look like a completely different game. However, they knew that if they released the game like that it would not be playable to any one with anything less than the top hardware on the market. At that time I had a 280, beaten only by the just released 295 dual pcb. It stuttered pretty badly. Even my 5770 Xfire couldn't manage it.
Even though it looked fabulous I just stuck it out. The game itself made up for it. Now though? well now I have a 470 overclocked and I can run it, but I certainly didn't spend that £200 last October to play Fallout 3 in hi def.
If you are looking to upgrade then sweet, do it for the right reasons. But tbh I would ditch the idea of Crossfire unless you are fully prepared for the headaches that come with it. I would sell what you have and get a 570/80 or something on a single card.
You won't get it much better by overclocking, going crossfire would be the best option even a 590 and 6990 only get around 60 - 80 FPS average.
Correct. And both of those will suffer with the problems associated with SLI/Xfire. Xfire is usually the major culprit due to the drivers. SLI is better than ever (given that it's Nvidias bread and butter flagship) but it's still far from being perfect. And if what you say is right about the FPS then it's money down the drain.