1. Last news i heard about when ETH transitions to PoS is early-mid 2017? Are there any recent news?
2. Is zcash going to always be GPU friendly or is it going to be mined by ASICs in the future?
Will i be able to make profit once the hardware is paid months ahead assuming i pay around 13 cents for electricity? What do you think?
(1) no new news, and the timeframe is still "up in the air" a bit not specific last I've seen.
(2) I suspect it will be as I dount it's going to get major market adoption that will keep the price and market cap high enough to make an ASIC worth building for it.
On the other hand, I never expected to see ASIC for X11....
13 cents for electric is quite marginal for mining. You might make enough to achieve ROI but probably *ONLY* if you can resell the used gear for close to new pricing when the profitability of actual mining for you drops to zero - or if some other coin comes along that is profitable for a while at your electric rate and you hung onto the gear.
ZEC and ETH profitability have been dropping pretty consistantly since about a week after ZEC went live - and I don't see any reason for that trend to change. It's still good for NOW, but I'd not bet on it for the long term - and when ETH goes Proof Of Stake that's gonna be a TON of rigs looking for a new home and HAMMERING profitability on anything else that is GPU mineable.
You should see some significant profits for a few months, though. Enough to ROI ... if you optimise your rigs well enough and have a viable exit plan, perhaps.
If you are only running 1 or 2 rigs, you're probably going to save most or all of what you spend on electric in your heating bill, this time of year if you're Northern Hemisphere.
20 rigs, you're going to have a TON of waste heat that won't be offsetting your heating bill and the electric cost is much more of a factor.
For perspective - last winter I was living in a older mobile home with mostly poor insulation. Ballpark 10kw of mining gear (mostly S5 and A2 ASIC units) not only kept the place 75-80 degree warm ALL WINTER IN AN IOWA WINTER, I had to keep a couple windows cracked with thermostat-controlled fans running in them to avoid OVERHEATING the place. I never turned the furnace on all winter.
Year before that which was one of the colder winters on record, "only" had about 5KW worth of mining gear - and didn't have to turn the furnace on 'till it got down to about 15-20 degrees (f) outside.
20 "common" 4-card GPU rigs will go through 7-9kw using RX 470/480 cards. That's a lot of heat.
20 of the 6-card type rigs would be 10-12kw. That's a LOT of heat.