Yes, these are running 36-37 TH/s @2098 give or take a bit depending on ambient temp...
Has anyone else verified these numbers on the latest batches? 56W/th vs 64W/th in high power mode is a pretty giant difference. |
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In the end, making an investment in mining is like any other investment. You are making decisions based on incomplete information about future events.
Charts lie all the time. You could look at that profitability chart for Jan 2017 to Jan 2018, profitability increased by 2.5X. The 1st 6 months of 2019 the profitability doubled. Of course, the chart will have an overall negative bias because gear has been getting more and more efficient.
After the S9 was released in 2016, profitability went down by half, but then was flat for 9 months before increasing all through 2017.
If you are bullish on BTC price, think diff might stall because S9s are getting shut down, and think asic manufacturers might not be able to keep up with demand because foundries are tied up pumping out new 5G components, maybe you could justify the cost.
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If I am an established big miner
I have 1 new cost that would be new gear.
my building = done
my wires = done
That is a good point. Back in 2016 there were not nearly as many huge mines already running. Now we've got 50ET of S9s already running and the only cost for those industrial miners to upgrade is new gear price and a bit of labor. |
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I think it's more related to popularity and the perceived risk of investing in mining. Back in 2016, I think it was a much harder sell than today to get investors to put big $ into large industrial farms. Then the run up to 20K happened in 2017, fees were out of control, and miners were making a killing. It got a lot of news coverage, and more legitimacy.
The fact that S9s are still profitable for 5 cent power after 3 years also would help convince investors to spend on new gear even with longer ROI time.
As for the price of gear right now, asic manufacturers currently can't get as much chip fab capacity as they'd like so it is limiting the amount of new hardware available. Limited supply = higher prices. If they had all the chip manufacturing capacity they wanted, prices would be lower, and diff would be rising even faster.
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I have never soldered a day in my life.
It can be pretty tricky to remove power connectors like that because the traces on the board are big and are typically connected to large areas of copper that act like a heat sink. The guide mikeywith shared has some good advice. The key is to get the whole board or most of it around the connector pretty hot before trying to use a soldering iron to melt the solder on the pins. If you don't, you can end up damaging the board to the point where it will be unusable. A pre-heater is nice, but you can also get away with a heat gun if you are careful. Or just put the whole board in your oven at 275 degrees F for 20 minutes or so and then work quickly after you take it out. Might be a good idea to wrap any other plastic connectors on the board with aluminum foil to protect them. This stuff for removing surface mount parts can help, but is pretty expensive. It is a very low melting point solder. https://www.chipquik.com/store/product_info.php?products_id=220001For a general intro to soldering, I like this guy. They are pretty long videos though. https://www.youtube.com/watch?v=J5Sb21qbpEQhttps://www.youtube.com/watch?v=fYz5nIHH0iYhttps://www.youtube.com/watch?v=b9FC9fAlfQE |
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what are the chances that, with absolutely no negative change in hashrate, we deviated as much as 1+ hour-long block interval away from the average of 10 minutes? Wouldn't it be more likely that there was indeed a temporarily decrease in hashrate which then caused this big gap? Probabilities aside.
it's impossible to know! but let's put it another way: 45-60 minute block intervals happen fairly frequently (more than once when I've been demonstrating Bitcoin to a newbie, and as well when I've been paying for something in person!) meanwhile, difficulty adjusted yesterday. Did the the difficulty drop?
Not sure what that has to do with a single day drop in nethash. If we had >114 blocks on the 23rd the difficulty would have increased more yesterday. that's correct, the difficulty increased despite the alleged hashrate drop. next question: is any hashrate drop in any way meaningful if the difficulty increased at the next adjustment? (I'm going to give you a clue, the answer begins with the letter "n") Not sure what you are getting at. Are you saying you think the number of blocks on any given day has no impact on the difficulty? Or that you don't care how much the difficulty changes, just if it goes up or down? |
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Looks like hashrate is back up. there is no evidence the hashrate ever fell it cannot go "back up" if it did not even fall Maybe I'm missing something, but it looks to me like there were only 114 blocks mined on 9/23. 596163 to 596276 you're disagreeing? 100EH/s at 11.8T diff should produce 170 blocks/day on average. If the nethash was actually at 100EH/s, the probability of getting <= 114 blocks is .00000319. Pretty unlikely.
90EH/s at 11.8T diff would average 153 blocks/day. Probability of <= 114 blocks is 0.000587, which is getting into the range of possibility, but still a once in a 5 year kind of event.
oh I see, you're not disagreeing, because you know that the rate of blocks getting discovered is probabilistic The "evidence" is circumstantial, and depends on if you think there is a greater chance that a good chunk of the nethash went down temporarily than a 0.059% chance of just having a really unlucky day for the network. I just wouldn't say there is no evidence. meanwhile, difficulty adjusted yesterday. Did the the difficulty drop?
Not sure what that has to do with a single day drop in nethash. If we had >114 blocks on the 23rd the difficulty would have increased more yesterday. |
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Looks like hashrate is back up. there is no evidence the hashrate ever fell it cannot go "back up" if it did not even fall Maybe I'm missing something, but it looks to me like there were only 114 blocks mined on 9/23. 596163 to 596276 https://www.blockchain.com/btc/blocks/1569268006726100EH/s at 11.8T diff should produce 170 blocks/day on average. If the nethash was actually at 100EH/s, the probability of getting <= 114 blocks is .00000319. Pretty unlikely. 90EH/s at 11.8T diff would average 153 blocks/day. Probability of <= 114 blocks is 0.000587, which is getting into the range of possibility, but still a once in a 5 year kind of event. Calculated these numbers with this poisson distribution calculator : https://keisan.casio.com/exec/system/1180573180Probability of getting <= X number of blocks in a day at 100EH/sec: X | probability -------------------- 110 | 5.736E-7 120 | 3.248E-5 130 | 8.260E-4 140 | 0.01017 150 | 0.06519 160 | 0.2349 170 | 0.5204 180 | 0.7910 190 | 0.9400 200 | 0.9889 Probability of getting <= X number of blocks in a day at 90EH/sec: X | probability -------------------- 110 | 1.574E-4 120 | 0.0033 130 | 0.0320 140 | 0.1560 150 | 0.4250 160 | 0.7307 170 | 0.9196 180 | 0.9852 190 | 0.9983 200 | 0.9999 edit: corrected to <= 114 blocks |
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It looks like there is discoloration on the heatsink near what might be the input rectifier. Ja ^^ Most of the time when I've seen this what actually happened is that the AC input rectifiers shorted and or one of the big raw DC filter caps shorted which directly overloaded the inrush limiter. In that case, think of it as a last-resort 'fuse' to keep the fireworks to a minimum  And yes, high line voltage surges will take out rectifiers/caps out in a heartbeat if the mfgr did not properly de-rate them. 3rd suspect would be the actual switching MOSFET(s) but in even a half way decently built supply that should be rare.  |
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Yeah, that last photo looks like the size of an inrush limiter for a power supply of that size. I'm not sure what would cause it to fail though. As NotFuzzyWarm said, once the PSU is on and running, the resistance of the thermistor would be very low, so it would require a very large amount of current to smoke it once it had fully turned on. I'd think it would be more at risk during power up when the resistance of the thermistor is high. If you turned the supply on when the input voltage was too high it could fry.
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Thermistors are not only used for temperature sensing but also as surge protectors. PTC (Positive Temperature Coefficient) thermistors are temp sensors, their resistance rises as temp increases. NTC (Negative Temperature Coefficient) ones are generally surge protectors, they start at certain (higher) resistance when cold to limit startup currents and as they get slightly warm from power flowing through them their resistance goes down to nearly zero to supply full power to a circuit.
In short - where is the bad thermistor located, near the AC power inlet and large bulk capacitors? If so it's a surge limiter.
That makes much more sense, and if it was a used as a sensor it probably would have been too small for the OP to get the part number off of. The inrush current limiter variety for an 1800W power supply is going to be pretty large. Any recent lightning storms? |
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A thermistor is used to measure temperature, in a PSU it would be used as a safety measure to shut itself down if it isn't getting enough airflow or ambient temp. is too high, or to control the speed of the fan, or both. It is possible the part just failed and that's your problem, but it is also possible that something else failed in the PSU that caused the voltage across the thermistor to go too high, frying it.
You could try replacing the part, and see if it works. I would not hook it up to any equipment you care about before measuring the output with a volt meter though.
Are the miners that were using those failed PSUs still operational (ie did you test them with working PSUs after they went down)?
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Newbies are restricted in other ways, why not just add locking of marketplace threads to the list? It would give established members opportunity to comment on obviously scammy posts so other legit newbies aren't scammed.
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Heard back from Cryptoboreas and now have gear shipping there in Nov and Dec. I'll update the thread with how it goes.
The expectation is that I'll have to pay 5% GST on the gear to get it into Canada, but I will not have to pay any additional tax on the hosting since I am not a Canadian resident.
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So I've never heard of MiningSky, which doesn't mean much as I don't use hosting. Just be sure to dig deep and be sure - I quickly found this article which appears to tie them to Miningsky.io - https://cryptonews.com.au/story/miningsky-the-future-of-blockchain-infrastructure-66506Again I'm only finding a few reviews but they don't look promising in regards to their clooudmining operation; if the companies are in fact related. I can't find any review about happy customers from their hosting facility, so proceed with caution just to be sure. Hopefully you hear back from Cryptoboreas if they have any space available. They are my first choice if I need to host or refer anybody; and that would be Hoth lol. If I hear of anything or something comes to mind I'll try and update you. I don't think Miningsky.io is related to Miningsky.com, although they both seem to have their offices in Vancouver, about 3.5km apart. Miningsky Technologyies LTD. is a subsidiary of SkyChain Technologies, https://skychaintechnologiesinc.com. Looks like they are a publicly traded company. I'll keep doing research though, can never be too careful. |
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The other thing to consider is what you would do with the gear after hosting. If you try to bring it to the US down the road you get hit with import fees again. Who are you talking to for hosting? If you don't mind sharing.
If it was no longer profitable or the host boots me after the contract and the tariff is still in place I'd try to find a Canadian buyer for the gear. If the host forced me to ship right away, I guess I'd either take the hit and pay the tariff to get them to the US, or try to find a trusted Canadian user to take them for a while I sell them (for a % of the sale). I'm talking with MiningSky in BC. I also contacted CryptoBoreas but haven't heard back yet. Have any other suggestions? |
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Importing gear, and taxes are the big ones.
One host I talked to says that he has to charge me gst on the hosting fee but I can get it refunded somehow. Sounds like a big pain in the ass.
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