Originally Posted by Benetanegia
Not true at all. Every evidence points out to the opposite. OCed GTX470 consume almost as much as GTX480. GTX470 and GTX465 power is similar compared to the huge difference between GTX470 and GTX480, despite the fact that 480 vs 470 means a ~10% reduction in enabled parts vs a ~30% reduction in GTX465 vs GTX470.
You assume that those cards use the same voltage domains. Usually, in the "lesser" versions of the chip's implementations, the GTX465/GTX470, we have chips that could not achieve the clock domains of the GTX480 at the required core voltage. Also the chips had different levels of transistor current "leakage".
In time the 40nm TSMC node was stabilized, and we can see GTX470 cards that are overclocked and consume less power then stock GTX470's of the past. For example the Gigabyte GTX470 SOC.
To continue my "theory" that AMD has yield problems. Having good yields does not imply to only have "working" chips. The chips have to achieve a certain frequency at a certain core voltage, in order to achieve an established maximum board power. If they do not, then the cooling solution must be adjusted, the vBIOS has to be tweaked, better components have to be used in order to provide cleaner power
and so on...
I do not buy that AMD was "surprised" about the GTX580 performance. AMD knows about nVidia cards long before even the rumors start, months before. nVidia knows what AMD is preparing for the future months before their release. Be sure of that.