The quick search on Google reveals that "the S5+ antminer offers nearly 3,000 more GH/s than the announced S7". How's that? Besides, the S5 uses 60 chips per miner while the S7 uses 162, so is this new miner in fact more efficient? Efficiency is not only about power consumption (operating costs), you should also take into account capital expenditures. In this way, if the new miner consumes half but costs twice as much (or even the same if it has the same hashrate), then you would still be less profitable at 12.5 BTC with it than with the old miner at 25 BTC per block per same price...
That's why Bitcoin halving may have devastating effects on its future (too many factors need to be "upgraded")
i was talking about the old s5, the s5+ was released with the s7 basically, but it's still not efficient liek the s7, it's a bulky version of the s5 with a slightly more better efficiency
It seems that your definition of efficiency is heavily lopsided. My understanding of efficiency is entirely economic, i.e. I don't care about power consumption and hashrates as such. All I care is the balance of costs and revenues. In other words, the miner that incurs less cost and brings in more revenue is more efficient (i.e. does more with less) than the one that does the opposite...
That's what all technical parameters ultimately boil down to