After doing research on using eyefinity display, I found that I need to use an active minidisplay port to dvi for my third monitor. However, I was hoping someone on the forum could tell me if I could use the three monitors on my (2x 6870) as 3 separate displays as opposed to one large display stretched across the screens for games. ie Main monitor - dvi, secondary monitor - minidisplay port to dvi, and third monitor (HDTV) - HDMI port. And if I do this, if my third monitor is off, will it still put a lot of strain on the cards to run the first/second monitor?
Depending on your needs, I think the easiest answer would be to disable Crossfire. Card One power the main and secondary monitors. Card two powers the HDTV. You will lose performance from not using Crossfire.
Another option, if you're not intending to use all three displays at the same time, might be to keep Crossfire enabled, but disable Eyefinity. Check Catalyst Control Center to setting up hot-keys to easily enable and disable monitors or swap displays.