if your stuck with an amd platform already then get a 960t and overclock the beans out of it... you may just get enough bandwidth not to bottleneck 2 680s but its doubtfull... even the highest end bulldozer will have issues at some point because of its poor single threaded performance. as you know not all games use 8 threads. in fact most use less than 3 so the 680 will choke sooner or later but sooner if you use 2 of em...
4 680's is a waste of time unless your gonna put em on a 2011 socker board as the pci wont have enough bandwidth to cope. even then i cant see any real reason to go that far with them cards unless your doing semi pro rendering... for gaming its just way past overkill as 1 card can max out every current game and give 60fps minimum even bf3 with x4 aa so 2 would be more than enough... you really would be wasting 1200 bux /900 quid... if you got 4 of em as 2 would never be used...
4 680's is a waste of time unless your gonna put em on a 2011 socker board as the pci wont have enough bandwidth to cope. even then i cant see any real reason to go that far with them cards unless your doing semi pro rendering... for gaming its just way past overkill as 1 card can max out every current game and give 60fps minimum even bf3 with x4 aa so 2 would be more than enough... you really would be wasting 1200 bux /900 quid... if you got 4 of em as 2 would never be used...