as i said AT THE MOMENT OF WRITING , stongest card providing HIGHER HASH RATE (no matter the power consumption) is RADEON PRO DUO ... 900 to 1100 hashes /s depending on the oc you apply ... of course the higher the hash rates the more inefficient it is... at 900 hashes is a bit less efficient than nvidia cards (4.5 w for each hash)
Per that number the TI only uses 156 w per hash?
The 1080 Ti can be set to do ~600 sols at ~150-155 watts. About 3.9 hash per watt ratio. You can get it up around 700 sols or higher but it will use the full 250 watts and beyond, making it very inefficient if you run it that way.
so running 6x 1080ti should be possible with a 1200W psu?
Just let you know it may be not that easy to get 6 cards working smoothly, there could be small issues here an there. I right now have 2X 1080TI FE + 1X 1070 on board, I could only start the miner first then EVGA OC software. If I do it the other way, miner will be freezing. In my case, I got 1080 ti up to 740 hashes before I cut its TDP limit to 80%, so definitely for a short while it eats up to 250W. Another stupid thing I could not explain is Nicehash is quite unstable with one of my rigs (I have two sets of 2X1080Ti+1X1070 on the same motherboards).
Better to find some one here with success then you exactly copy what they did (especially get the identical motherboard/OS)
that's a really good point . . these problems remind me of car problems . . massive headache! currently thinking of simply trying to add another SAPPHIRE Vapor-X Radeon R9 280X DirectX 12 100363VX-3L 3GB onto the rig that already has 5 of them and call it a day if I can get that running smoothly