i think it's better to wait for bitmain to release the new antminer s10 or s11 with better efficiency, i hope they make more model for lower consumption too
Gonna be a fairly long wait for something like that - there is no more "catch up to the state of the art" allowing new MUCH higher efficiency models every year or less, we're now looking at having to follow the "state of the art" norm that is a lot closer to "new process node every 4-5 years or so" instead.
Also, the next two or three process nodes are running into major issues, as the major semiconductor makers hit the end of the road on being able to keep pushing silicon to smaller feature sizes - Intel and IBM have both stated that "10nm is the end of the road for pure silicon" - this is likely to slow the "new node cycle" noticeably at least for a while.
Bitmain at this point has no REASON to bother releasing a miner based on a new chip, even if they are working on a more efficient model for the future, as they are already selling THE most efficient model on the market.
What they need to do is some serious work on making the current S9 models A LOT MORE RELIABLE - both the S7 and S9/R4 (and to a lesser degree the T9) have shown a lot lower reliability than the S5 did.
I could see a small possibility of them releasing a "S9 lite" type model, with only 2 hash boards and resulting lower power consumption, but am not holding my breath on such a device.
if they keep waiting before releasing another one, they will lose profit in the end, right now miners are increase the diff at insane rat, because there is a lot of room for profit
but will not last unless the bitcoin value continues to grow also at insane rate, within one year or two bitmain will be forced to released another one if the value is still below $2k
