Bitcoin Forum

Hi Guys,

Looking for recommendations what kind of 2nd hand rigs would you be using if i have shophouses with maximum electricity capacity of 70,000 watts.

We have relatively cheap electricity and looking for fastest roi.

Our monthly operating costs is about:

$600-$800/month rental

internet is about $50/mth

How cheap? every cent matters here, another point you need to consider is your budget, picking the "right" piece of mining gear isn't based on just one factor, you can buy an old  T9 for maybe 100$ and hit ROI in 2-3 months, but then you can only make about 2.2k of profit a day (before the power bill and rent) while consuming all those 70kw, on the other hand, you can get the 30w/th gears and make a few tens of thousands a month, but your budget needs to be so high and ROI won't be great, finding the right balance of everything requires a lot of information.

If you are able to provide this info, then we can talk, keep in mind that nobody will give you the "best" gear to buy, but at least you will be able to use the information to make an informed decision.

if electricity is free... which rigs would u choose based on those fixed cost?

Budget will be the next point i consider, if budget is limited I will go with S9j or S9i, that will give you about 800th or 4.5k a month based on the current figures.

If budget is flexible, i would go with Whatsminer M21s, that will be 1.15ph or 7k a month, total cost will be at almost double 40$ per th vs 20$ plus for S9s.

However, the M21s will most likely live a lot longer and you will have a lot less gears to manage, less wiring and whatnot.

if i am looking for something in between whatsminer m21 and s9 what would you recommend? if my budget was in between these 2 machines.

Nothing really falls in between, the S9 does on average 80w/th with custom firmware (as low as 72w on some gears if downclocked really well), the M21s is about 60w/th, there is nothing that does anything above 60w and below 70w which I would recommend to anyone, if the M21s are above your budget, get S9i/S9js, or you can always mix two gears, maybe fill 30kw with M21s and 70kw with S9s, that will give you an overall (in between) option.

If your electricity bill is free and stable for a long time. I recommend Antminer S9j (14.5t 1350w). Each machine can earn you around $3 per day. s9j is about $200 and you only need 68 days to get your money back. In addition, there is an s9j in my mine that has been used for more than 4 years. He still has no problems and continues to work. I think it will be fine for him to work for another two years.