Currently i am running a phenom II 940 BE 2 3.4ghz, 8gb ddr2 1066mhz ram, 1000watt psu, and a hd 4890 video card. i found a good deal on the hd 4850 x2 and I was lookin for some feedback on whether it would be worth the upgrade on a 23in 1920x1080 monitor. Also any feedback on mixed crossfire would be nice because perhaps I could still use the other card if i decide to buy the hd 4850 x2. thanks in advance