@ Phobo$ : sorry if someone already told you, but disable Crossfire when playing Div2. I'm playing it on a similar system, which only has a single 4850 card, and I can play it fluently with everything on high.
The other tips given in this topic are gold: try playing with the settings of the game and see what works best for you. You can run this on fairly old computers, but you just need to be able to set the game's resolution to 800x600 or 1024x768 or 1280x1024 or similar "low" resolutions, and then turn off everything and pull every slider back to the lowest. Then try to change a couple of options and see what works for you. It is trial and error, but I'm sure you'll find a setting in the end that is right for your computer.
Also the defrag/contig idea is important, along with "install on your primary / OS drive" and make sure nothing much is running in the background
