I have been trying to get my head around which of these to consider when building a multi-monitor setup for FC and A-10c.    
AFAICT, eyefinity can do individual monitor processing as well as combined large screen (see my post here), but I would dearly love clarification.   
What about crossfire or sli? perhaps 2 x 5850's, but then the cost, the cost :(, and then the power consumption, how much power would 2 of these cards need?   
Do any of these technologies benefit FC or A-10c ?   
What about a 4 monitor setup, 3 upfront in cockpit and one for Helios (lower down rendering MFD and other panels, probably need to be touchscreen) ?   
I would really appreciate people in the know shedding light on this as the more I research it, the more questions I seem to raise.   
Many thanks   
EDIT: Crikey! I have just come across a fourth option - Softth. Oh my god where do I even start?