[Solved] Question about Eyefinity, and Crossfire

I wanna ask these questions. I know I can surf around but these past days I've been reading and theres at least about 2 RESPECTABLE websites who don't know jack about Eyefinity (both of them said that Eyefinity can be up to 3 monitors even without Digital Port, since you can use a DP to DVI adaptor, which is WRONG as you need ONE DP monitor to have Eyefinity). And I have faith to you Tommies that you know more than them

Anyhoo, these are the questions:

1.) If, for example, I crossfire 2 HD 5870s, can Eyefinity still work? Or only one Vid card can support Eyefinity?

2.) If I have 2 22" monitors that have a native resolution of 1900x1200 resolution, and I have another 22" monitor with Digital Port, but its native resolution is 1680x1050, will the latter monitor affect the quality of Eyefinity in games?

3.) In principle, if you have 2-3 monitors running in one video card in your rig, will it affect FPS and overall performance in gaming? Compared, like say, using only 1 monitor with the same other hardware?

4.) Is the restriction of HD 5870 and 5850 to require a Digital Port monitor for Eyefinity a DRIVER issue or a HARDWARE issue? Can we not see in the future, future drivers that can allow a Digital port to DVI adapters and 2 DVI monitors supporting Eyefinity?

Thanks....really cleared a lot of things

BTW whats a DAC?

ok...thanks