ok, thanks for the explanation.
So this 2.2 number was just pulled out of someone's arse then?
Well I thought a little more and have JUST one way to get to that number... add another 256MB module but that's too weird to be true because a never saw a bus interface of 288bits.
9 x 256MB = 2.2GB @ 288bits = 180GB/s bandwidth
This other module can be a similar one or a EDRAM module near the GPU... again that's too unrealistic and hilarious to be true.
The others specs are realistic at least.