The amount of transaction fees per block may have been 4% over the last 6 months but in the last couple of months, it has been less than 2%. So antpool may actually the best bet now if getting the most reward before the halving is top priority. The issue is that if enough people are mining on pools that don't pay transaction fees, it makes it possible for the pools to send spam transactions to artificially increase the transaction fees. Bad news for the network. Also, just normal market conditions can cause the transaction fees to rise. So between now and the halving, it would be best to find a PPLNS pool with enough hashrate for a short rampup that pays transaction fees. After halving, ramp up time and pool hashrate is only important if you can't deal with the variance.

For the above situation, you'd spend  $14,850. You might get $100 per S9 with PSU, so $2200 back, net cost $12,650 to get an additional 240TH.

With free power, and BTC price of $6900, the 240TH makes about $31.50 per day, so 402 days to make back your investment if the diff to price ratio stays constant. Of course, the halving is way less than 402 days out, so it is actually worse than that.

If you only bought 1, the ROI calc would work out the same.

If you think that this is the bottom, and you don't think your S9s will be profitable with your nearly free power after the halving, then it would make sense to start upgrading. If not, the #s don't look good to me.

If your power cost is lower than most of the industrial big guys, then you'll always be able to just wait for them to start liquidating their unprofitable gear and buy it for very low cost. You take on a lot of extra risk paying a premium to upgrade early. You can buy 56TH of S9s right now for $400, maybe even less. If the break-even power cost for a T17 or A1066 hits 6 cents, you'll probably be able to get them for $400 instead of $1400 now.

Another option is to find a host to send new gear to and keep your S9s running with your super cheap power. When the new gear is no longer profitable at the host you can move them to your location and retire the S9s.

I'm guessing OPs best course of action is to not upgrade yet.

If "basically free" means <3 cents, don't upgrade yet.  Right now a bunch of S9s are being shut down by these guys with 5 to 6 cent power, and the price of S9s is dropping. OP should wait until the price for 60 W/TH gear (T17, A1066, etc ...) to crash when the 6 cent guys are no longer profitable with it. At that point, upgrading would make sense.

If OP is barely profitable with the S9s (ie 5 cent power), then it would make sense to upgrade now.

In that case, I'd be concerned ... you are sure those are 20A breakers and not 30A? And you're running just normal "low power" and not "enhanced low power"?

Just because it has worked for a few months doesn't mean it's not a fire hazard...

If they are 20A 240 circuits you have 3840W of safe continuous power available, and your current setup isn't really safe even if you are running enhanced low power at 1000W per S9.

If the breaker panels are located close to your PDUs and everything is open (not wired through walls), it may not be very difficult to rewire for 30A circuits.

In that case, you would have 5760W per PDU available.

T2T-30T run 2200W if you believe the manufactures specs, so you'd only be able to run two. Since you say your power is basically free, this would not help. They are only marginally more efficient than your S9s, so it really isn't going to help any way you look at it. If you were to re-wire everything to fully utilize your 500A service with these, you'd only end up with about 20% more hashrate.

You could run two 50TH T17e on a PDU. They are $1007 + shipping + tariff for Jan delivery. So about $1350 each delivered.  Just buy as many of those as you can afford, and fill the remaining capacity with your existing S9s. So with 15K, you could get 11 T17e which would replace 22 of your S9s, giving you about 240TH over what you have now.

Same would work for 64TH S17e, but they are not currently available.

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Also another thing to keep in mind, if the service is residential the power company is not expecting you to utilize 100% of the capacity of your service. It may be wise to take a walk outside to see what rating the transformer that your service is coming from is. Many are marked on the outside with the KVA rating. If you are trying to use 500A of 240V, the KVA rating should be higher than 500A x 240V = 120,000VA, or 120KVA. Don't normally see transformers that big in residential areas.

This is an interesting article: https://community.openenergymonitor.org/t/us-200-amp-service-explained/4219

What voltage is your electrical service? 240V? 208 3 phase?


Are you sure each PDU is on a 20A circuit? Doesn't seem like you could run 4 S9s on a single 20A circuit. With new firmware running 1250W per S9 you'd be pulling close to 21A at 240V. Keep in mind that for continuous loads you shouldn't exceed 80% of the circuit capacity, so a 20A circuit maxes out at 16A continuous usage. Did you mean 30A circuit?

I guess it could work if you are running 208 3 phase to the PDUs.

53 W/TH vs 63 W/TH is a giant difference. What is the ambient temperature?

I'd be interested to see what the average is over a few hours using kWh meter.

Did they come direct from Canaan? I still have not received a shipping notice from Blokforge on my 1066 order.

Meanwhile, my Dec. batch S17 order just shipped, and I received $800 credit per S17 that I used to get more S17 pros that are already hashing.

I used a credit of $3984.78 and coupons for $1104 in my order.

Just went back and saw that and was about to edit my post but you beat me to it. Yeah, still a lot of power for a single cable. Pretty much requires you to go 240V. 208V is over 16A , right near the limit of the C19.

Although I did see a m20s running when I visited my host a few weeks back. I felt the power cable and it wasn't warm. I think they are running 240 though and the power cord looked really beefy.

Interesting. But the way it's worded in the tweet it sounds like the 88T may be at a full speed and the 38 J/T may be at a low power mode.


If that is the case, then at full speed this thing could be pulling over 4kW! I can already smell the electrical fires.....

You can make the numbers work if the government subsidizes the cost of the solar in one way or another. But without tax dollars helping out, you're looking at a cost of more than 10c/kWh if you use all the power from the array over a 25 year life. That's if you're doing a grid tied array and the power company is giving you even credit for the power you put back into the grid. If you are not grid tied then the battery system just makes it more expensive. If you are doing a huge industrial array it could be cheaper, but still not as cheap as a decent industrial power rate.

My order actually expired before the credit was applied. When they applied the credit the order went active again and I think I was given 4 days to wire the difference. So no need to worry about the order expiring.

Seems like a "too good to be true" situation.  23.2 W/TH at $31.45/TH. I'll believe it when a trusted user gets a demo unit and reports back.

Doesn't look too good. On top of being late, the S17 pros I ordered were about the same price as these and I already have them. Would be nice of them to at least send out some coupons to compensate. If they reduce prices on the 11 series to be more competitive with Bitmain and issue some coupons I'd order some. But right now you can get a S17+ for less than the 1166 and get it a month earlier. I'd pay a bit of a premium for the Canaan gear over Bitmain, but not that much.

Anyone get their Nov. batch 1066s delivered yet?

I'm still waiting on a shipping notice for my order from Blokforge. They responded to a request from me about the status of the order 3 days ago saying the miners were on route to them from China.

I'm not sure the debit card actually helps with sending money. I thought it was more for taking money out of the account. I got the card as well since it seems like it will be very useful for getting money when traveling internationally without getting screwed by the typical exchange fees. The $20 should show up as a balance on the web site, and you should be able to send it out now.

I used an ACH transfer initiated from my bank to move money from my bank account to transferwise, and then used that balance to send the wire to Bitmain. I think you can do it in a single step but it might cost a bit more. If you select "send money" on the web site you can see what the options are and what they cost. If you want to test it out, you can send a transfer to your own bank account.

Also, delaying the refunds until next year may make their books look better for their next IPO attempt...

My 3 S17 pros bought on credit were delivered yesterday, now just waiting for my host to get them up.

For anyone who wants to order by bank transfer, check out https://transferwise.com

They have by far the cheapest international wire transfers, and you can cash out from many exchanges directly to them with no fee using ACH.

The cost for my last wire transfer to Bitmain was $4.60 vs. $45 from my bank directly.

bump

Asking price lowered to $115. Also, feel free to send me an offer.

You can't combine the 10% and 30% coupons in a single order. I had to place two orders and used all my 30% coupons in one and some of my 10% coupons in the second. I spread my credit across the two orders.