It seems like it is.

According [1] a 1080 Ti can produce about 675 hashes a second for Zcash. Using [2] we can see that one card would net him about $2.5 per day. For six cards we get ~$450 per month which is enough to pay his electricity bill and probably internet costs.

The graphic cards are quite costly and the payback time for the card thus pretty long.

[1] http://zcashbenchmarks.info/ [2] https://www.cryptocompare.com/mining/calculator/zec?HashingP...

Good question..... I wonder why they skipped it. They mentioned electric bills , and skipped internet data plan.

From the little know I have not seen mining via Wi-Fi. I know of a country where everybody is using Wi-Fi, is it possible to mine in such a place?

Mining doesn't need to send much data, so it shouldn't matter at all whether you use wi-fi or dialup etc.

Please could recommend one (Wi-Fi) rig machine ?

Normally you use a computer, so all of those if you add a wifi adapter. If you have some kind of ethernet-only machine then use an external device (like another computer, or a router, or a raspberry pi) to turn wifi into ethernet.