I am planning to eventually have 2 x2900xtx's in crossfire. I have never used crossfire before/dont know how it works. I plan to get a 30 inch monitor from either dell/hp(odds are dell because it constantly goes on sale for 500 dollars cheaper) but dells only has 1 dvi input as opposed to hp's 4. I was wondering would I need atleast 2 dvi inputs for each card or how exactly does crossfire work?