As far as I know with every jump to lower NM process the performance/power consumption ratio improves by significantly less, right?
for example, when we switched from 68nm BTF singles to 28nm antminers, we were humming with about 661% more hashes per second for the same watts
(BTF single 68nm, was doing 60ghs with ~300W at the wall and antminer S3 28nm does 450ghs with ~340W at the wall, so we have 5W per gigahash in the first case and 0.75W per gigahash in the second. Which is 6.617647055 times more)
The 20np Neptune claims 0.57 watts per Ghs which is only 1.315789474 times more or 31% better performance
can someone speculate based on that what improvement we will have with the 16nm technology?
Other interesting points of speculation would be when we can expect 16nm (and further)
That info will be useful for some longer term planning