Haldi is right, outputs on ALL subsequent amd cards in crossfire are disabled (i have 3x 7970) so effectively you only have 2x mini dp. These are best as they have the highest bandwith. Also im not sure if you need active adapters (if going to dvi) or if all passive are ok (i think so but check) with the hub.
For best results you will need 2x MST hubs BUT wait a few days until there is a definitive answer to this:
http://www.wsgf.org/forums/viewtopic.ph ... 8&start=30One of the displays randomly drops out from the hubs, sounds like it could be a firmware issue or just teething issues with a new product but just be aware.
PS: Is this the card you have? (If not could you provide a link so we know exactly what you have)
http://www.sapphiretech.com/presentatio ... id=1&leg=0EDIT: Just having one of those mornings (Should have woken up before I got out of bed...LOL)
For 5 displays probably best bet is to get something like this to xfire: (To keep brands the same)
http://www.sapphiretech.com/presentatio ... id=1&leg=0The flex series cards mean you can use all outputs simultaneously (But you will probably still need active mini dp adapters)
or any of these cards:(As haldi stated)
Here is a list.
http://www.wsgf.org/forums/viewtopic.php?t=24334You can xfire dissimilar 7970s, just use MSI afterburner or similar GPU app to synchronize base & memory speeds. (They can usually handle 10% OC without any problems, just set the power limit to +20%)