Your crazy imo haha
1070's ? dude your like a YEAR too late to build a farm with those lol, you are gonna be lucky to ROI probably before they start bring in like 1$ a day each

Plus all that wasted space, did you not consider DENSITY LONG TERM?
New mining specific cards are coming out that are gonna DUST your whole farm if you have 1070's, did you consider THAT?
Im just getting RID of my old 1070 for POWERFUL cards, 1080, 1080ti, and stacking my coins for the new mining specific card + volta and vega
Like you literally picked the worse time to choose 1070, o and in 2 months or less they will be 1/2 price
I've read about those cards, one article said they will not be available at the consumer level...isn't that rigging the game?
Another thing to think about is ETH switching to POS someday (this year?)
So you are saying he should go with 1080ti? It's performance/watts vs price (and availability). I few sites (could be wrong) say the 1080 is only 18-20% faster...does that sound right?
Well there's ALWAYS something to mine, it's just WHEN ETH goes PoS (who knows when but COULD be 6 months from now) there's gonna be literally 1,000,000 hungry GPUs needing shit to mine, so those with 1070 (and 470/480) are gonna get SLAYED in profitability imo
IF we can GET tho miner cards, well thats to be seen, yes

There is hope tho! New coins all the time and Nvidia can handle ANY algo like a champ unlike AMD, but to build a farm on that hope of new coins is SCARY to say the least.
Also, 1070 is at the "end of its price point", it WILL go down soon 30 days even
1080 at 20% more powerful, and only 10-15% more price? seems logical to me! think RESALE as well
1080ti will NOT win in price for performance, but in 2 years it will still be profitable AND still resell well (if you get the good brands/models)
PLUS, ROI extends pretty fast when you have to buy WHOLE NEW RIGS every 5 cards just to keep up with 1080ti buyers :/
DENSITYonly my 2 satoshi's of course

i own 1070's as well
Totally agree, we should wait for new gens GC and dedicated Mining GC...