oh, dear
can we get more trolling? do you guys even understand wtf you are talking about?
Let me put this in a way that even you guys can understand (though I still have doubts):
HBM was developed and used by AMD in fiji because:
-gets rid of hot and power hungry GDDR5
-simplifies PCB design, look at the cards size
-even at 500Mhz it gives a lot more bandwidth than superclocked GDDR5. next gen gpus from nvidia and amd are gonna be huge leap in performance. Look even nvidia is doing HBM next year, so probably they do need that bandwidth. So if nvidia expects their next GPU to need hbm type bandwidth then AMD is not far behind as well, or far ahead (whichever way you look at it)
-having hbm in fiji is pipecleaning process: old arch, old process tech, brand new memory controller and memory interface. Come next year, AMD will have plenty of in the field experience with HBM, and when releasing next gen GPU, they only will need to worry about process and their GPU arch changes, while nVidia will be trying to sort out new GPU arch, new memory controller, new memory interface, new process node at once. Companies much more resourceful and experienced than nvidia rarely pull of such release without issues, most of the time they don't even try such things in order to minimize the risks of something out of all new things going wrong.
and if some crazy enthusiast OCs HBM to 1Ghz, how is this AMD fault, kids? How did AMD waste time while some OCer was playing around with AMD card in his basement?
and mister smart arse fs123, please enlighten us, how would you increase core performance on 28nm node with GCN arch? Please, the floor is yours, if you want I can bring paper and pencil for you, but several hundred million pounds/dollars will be in your expense, while you are coming up with this revolutionary way of designing chips.