Q: Most reliable SHA-256 Asic Miners

[cryptostashman]

Hello all. I am totally new to Asic mining, I used to mine on a gpu rig at home 3 years ago, but never had the attention to use Asic miners because of their high prices and unavailability in my country.

Currently I received an offer from a friend to start an asic mining farm since he have an access to very cheap energy (around 2.5 cents per Kw) of up to 250KW. So efficiency is not a problem here.

I found out that old Asic miners a lot cheaper these days than before, but I'm struggling to choose from a lot of manufacturers like bitmain, Canaan, innosilicon, Aisen, etc. Doing some research I found out that maybe Canaan has a good review of users, but bitmain is more easier.

Anyway, my targets are old S9's, Avalon 841, 851, 852, Aisen A1, innosilicon T1, T2, etc. Those which are cheap ASICS.

I wanna know which asic should I go with? My target is cheaper cost with higher TH and reliable equipment. Minimum 10TH to 40TH for each miner. I hope I can find the help here.

If anyone has a reliable seller too I will be glad to contact them.

Thanks alot.

[mocacinno]

hmmm... 25 cents/Kwh and mining with older gen ASIC's... sounds like a recipe for disaster to me...

I stopped mining years ago, i think it was when my electricity price reached about 20 cents/khw, since then the diff has skyrocketed.

I did a quick calculation simulation here... The S19 pro draws 3250 Watt at the wall and hashes at 110 Th/s:
https://www.coinwarz.com/mining/bitcoin/calculator?h=110.00&p=3250.00&pc=0.25&pf=0.00&d=20823531150112.00000000&r=6.25000000&er=1&btcer=34366.17000000&ha=TH&hc=2407.00&hs=0&hq=1

You'll make $3.3/day

If you'd replace this with an S9:
https://www.coinwarz.com/mining/bitcoin/calculator?h=13.5&p=1350&pc=0.25&pf=0.00&d=20823531150112.00000000&r=6.25000000&er=1&btcer=34366.17000000&ha=TH&hc=2407.00&hs=-1&hq=1

You'll LOSE about $5.3/day... That's right, each day you mine with an S9 with a power price of 25 cents/kwh, your power bill will be $5,3 HIGHER than the value of the BTC you receive from your pool.

Bottom line, even if you'd buy a brand new ASIC, it would cost you $3770 + S&H + PSU + import duty + shelves + wiring + AC + ... It would take you 10 or 15 years to recuperate your investment IF ONLY the diff would no longer rise, the price would stay fixed and the block reward wouldn't halve.

Mining with anything less than latest gen gear would hemorrage money straight from the start.

At 25 cents/kwh, don't mine... Sad but true... Mining is for people with a power price < 10 cents/kwh

[cryptostashman]

I'm sorry I corrected my post.

It was a mistake while converting my currency to usd.

It's 2.5cents per kwh

[mocacinno]

I'm sorry I corrected my post.

It was a mistake while converting my currency to usd.

It's 2.5cents per kwh

That's more like it

For an S9:
https://www.coinwarz.com/mining/bitcoin/calculator?h=13.50&p=1350.00&pc=0.03&pf=0.00&d=20823531150112.00000000&r=6.25000000&er=1&btcer=34366.17000000&ha=TH&hc=2407.00&hs=0&hq=1

So, basically $1.8/day net profit... Take the price you'd pay for the S9 + PSU + S&H + import duty + ... and divide the sum by $1.8. You'll see the the amount of time (in days) you'd have to mine to recuperate your hardware investment. If you trust the diff to remain stable, the price not to drop and it's before the block reward halves, you might have a shot at making money...
Some people also include the resell value of their hardware in this calculation... But be carefull: these ASIC's tend to break after a while... You don't have any guarantee you'll have something to resell in 6 months...

[NotFuzzyWarm]

The most reliable are the Avalons. Damn near bulletproof plus they are very tweakable for speed/power.

When using the A8xx, be aware that while you can run you to 20 miners per-controller you CANNOT mix miner types on a controller. The 841, 851, 852 all need a separate controller for each model. Also while each AUC dongle can support up to 5 miners in a string (and max 4 dongles per controller) yuo get better results with less stales if you keep it to 2-3 miners per string.

[cryptostashman]

Actually we did the calculations, and since rental is not a problem since my partner is the owner of the place.

And we are accepting the fact that bitcoin might dip in the near future. And we found out that our investment can have a 3 to 4 months roi. Since when btc dips usually the difficulty will drop. And we are planning for a long term holding btc.

So my question now is which is the better option of hardware that is reliable enough with less maintenance and problems.

[NotFuzzyWarm]

Then that would be the Avalons. Over the past few years I've ran several dozen of them from A721's on up to the latest: Zero major problems and just 3 dead fans. Frankly I doubt any other make is more reliable.

Only one I would say to avoid is their A921 series and that is just because the 841's can be made to be just as efficient in power/hash rate. It also uses a larger 140mm fan that can be rather hard to find a replacement for.

[philipma1957]

Not to argue  about the Avalon 841 vs the bitmain s9.  Availability and price matter.

Ie at 250 for an s9 and a psu if the s9 does 13th that is about 21 cents x 13 = 2.73 a day

the A841 at 12th makes about 2.52 a day

you need to get them fast and at about 250 a unit with the psu included.

if they burn 1200 watts that is 30 kwatts at 2.5 cents power cost is  75 cents

so the s9 clears 1.98 a day today subject to change and the A841 clears 1.77 a day.

so if you can find them at 250usd with psu included you could turn a profit.

Ebay has a guy selling s9 with psu for 249.99

https://www.ebay.com/itm/Bitmain-Antminer-S9-w-psu-Runs-on-120v-household-current/324442107132?

I don't know a thing about the seller. He has about 14-18 for sale.

minefarmbuy has the t15

https://minefarmbuy.com/product/antminer-t15-3p/?v=a284e24d5f46

but I think it may not work for you at this price.

[cryptostashman]

Then that would be the Avalons. Over the past few years I've ran several dozen of them from A721's on up to the latest: Zero major problems and just 3 dead fans. Frankly I doubt any other make is more reliable.

Thank you for the information.

Well, if I'm to choose from A841, A851, and A852. Which one should I get? Specially I can't find deep information about the A852.

Only one I would say to avoid is their A921 series and that is just because the 841's can be made to be just as efficient in power/hash rate. It also uses a larger fan that can be rather hard to find a replacement for.

But if I found some cheap ones which has less $/TH price.  Would I buy them? Let's say I found A852 for $200 that's around 13.33$ per TH, and I found A921 for $240 which will be valued @ $12/TH. Is it worth it to save more with the A921 and deal with the maintenance or no?

[NotFuzzyWarm]

I have no experience with the 851/852 so not sure about their speed or efficiency. Frankly I'd get the 841's, main reason is that there is a ton of PSU's out there for that power range. Max a 841 will pull even when over clocked is under 1,500w. As I recall the 85x series push 1.5-1.6kw and I know the 921 will pull up to 2.2kw

Highly suggest you peruse HagssFIN guides on the Avalons:
841 guide & review
851 review/guide
A7xx & A8xx troubleshooting and repair guide

[philipma1957]

I tested a851/a852 they sucked do not get them.

a841 are very good.

and s9 is good.

my single a921 was better then the a851 i had.

if you have a deal for the a921 and have 240 volt power there is a seller of really good psu in the marketplace.

it will do 2400 watts at plat levels.

7empest is the seller.

[7empest]

... 7empest is the seller.

Thanks for the shoutout Philip.

@crytpostashman, there is a PM for you.

[favebook]

Short answer:

If you are looking for reliability, durability and stability, my order would be this (from best to worst):

Canaan>Whatsminer>Innosilicon>Bitmain (with exception of S9 and maybe S19 units).

Long answer:

I've had very few of Canaan and Whatsminer units, but they were always reliable and I never RMA-ed a single one. Everyone I knew who used these had really good "luck" with reliability compared to Bitmain.

Innosilicon is a bit different story, I've had a tad bit more of units that went through my hands or that I used personally. They were all really good and with exception of one T2T's PSU giving me blue smoke after solid 2 years of working (tho it was put through hell - it was used in miner oil a few times, then it was OC-ed to maximum "Performance+" mode during summer).

Bitmain is a complicated one... S9 were really good for me and everyone I knew personally. Out of 100 units that I had and later sold locally, they are ALL still working with OC (using exactly 1.8kW or less - depending on PSU). X11 and X15 were short series not worth mentioning. And then came X17 series, pure hell of units, I've had 75% failure rate on them. S17e was only unit that didn't break even through OC during summer. S17/S17Pro/S17+ all broke even if they were used on factory settings or underclocked. I would never recommend anyone to buy that generation of miners. X19 seems to be better, but more time has to pass so we can determine exact failure rate on them.

[philipma1957]

it is amazing how i managed to be 17 for 17 on my s17pros. still all work just fine.

s9s were good in general.
if he could score a841 he would like them.

with his 2.5 cent power i would look for gear that can shift psus

s9 ,a841, a921 would all work well with the psu 7empest sells.

[mikeywith]

I don't have any experience with Avalon mining gears but I trust the other gentlemen's judgment, so reliability wise, I think Avalon beats bitmain easily, if I had to choose one gear in the world it would be Whatsminer M21s, but since that isn't in your list I would go with the S9.

While an Avalon gear could be more robust than S9, the latter is a lot more popular and has a variety of custom firmware that supports it, so you can get anywhere from about 10th at 800w range to a lot more powerful gear of 15.5-16th, also the spare parts are available everywhere, of course, you want to avoid the (K) and the (SE) versions as those are far from reliable.

With that being said, the Avalon 841 and the Bitmain S9 are pretty similar in terms of efficiency, so between the two, it would be a matter of cost per terahash.

[cryptostashman]

[...]

Noted.

I Lost a deal with the 852s. Currently I have a deal with 821s but they're too old. But price per Tera is so cheap that makes me think of taking the deal, and whatever I save from the difference of my other deal with s9js would give me the chance to purchase the latter.

[...]

This is a very good information. Thank you a lot for this.

I think I accept the fact that Canaan is a better choice, and the good thing is it can save wiring Lan cable because of the array style it's using. My only problem now is to look for another offer from the suppliers since the 852s might not be the choice now. I'm thinking since I have a very cheap rate and a good supply of power I can still mix my farm between 821s 841s and s9js if I can get my hand on a very cheap 821s.

Yesterday I had a deal for 821s @85 CAD.

[...]

My list is open since what I care is reliability + cost/Tera. I might be open to whatsminers too.

[NotFuzzyWarm]

Yesterday I had a deal for 821s @85 CAD.

I'd say take it. The 821 is only about 1-2 THs slower than the 841 though again, remember you cannot mix different models on 1 controller.

Regarding the mention of 3rd party firmwares for s9's - keep in mind that most charge you a couple % usage fee that is taken by the miner periodically changing to what is called DevPool. The Avalon's have no need for those 3rd party firmwares because they already support an extensive list of built-in performance tweaks to change clock rates, chip voltage, fan speed, operating temp, etc.

[mikeywith]

keep in mind that most charge you a couple % usage fee that is taken by the miner periodically changing to what is called DevPool.

Ya mainly 2-3%, any firmware that asks for more should be avoided, and I don't think it "periodically changes", at least not for Vnish, they claim "Parallel mining" which seems to be the case when you observe the reported hashrate on the pool, it doesn't seem like it discounts at all, but you do see that hashrate being equal to what shows on the pool minus the fees so a few gigahashes are going to be lost

The Avalon's have no need for those 3rd party firmwares because they already support an extensive list of built-in performance tweaks to change clock rates, chip voltage, fan speed, operating temp, etc.

That's great, I wish Bitmain would do something similar to Avalon, you know none of us really want to pay those dev fees, but the stock firmware is too bad, the custom firmware devs knew that and they know there would be a huge market for custom S9 firmware, one reason they didn't touch the Avalon is probably the fact that Avalon users don't really need a custom firmware since the custom firmware does what they need.

My list is open since what I care is reliability + cost/Tera.
I might be open to whatsminers too.

Cost per terahash won't favor Whatsminer M21s, it's a newer generation gear, not in the S17 range but somewhere in between, it's about 56w/terahash, but you should keep in mind that most gears mentioned here including my own pick of S9 are gears that have been around for way too long, the last time Bitmain made an S9j/S9i was probably around 2018 or very early 2019, so most gears in circulation are  AT LEAST 2 years old and above, the average would be 3-4 years, a very critical age as far as I am concerned,  pretty soon most S9s on planet earth will either die or go through a major rebuild which might not make sense in terms of cost.

In other words, IMO, you should hedge yourself against the lifespan of these old gears buy acquiring a few newer and more efficient gears, while your 2.5 cents Khw rate is very good, it's isn't perfect, so eventually, you will be kicked out by the efficient gears, so maybe 20-30% of your hashrate should be in the 60 or less w/terahash.

[philipma1957]

yes grab those 821's they are decent gear.  good price. they use 100 watts a th

so 11 of them is about 100th and uses 240kwatts at day

240 x 2.5 = 6 dollars a day in power

100 x .1945 = 19.45 dollar a day in earnings

13.45 profit

cost is 11 x 66.54 = 731.94 for the miners. not sure if you get psu's

the guy I hooked you up with is 30 for a real quality psu.

so if you are 732/13.45 = 55 days

if you need the psu's

1110/13.45 = 83 days

Not sure show much you are sinking into it but your margins are decent.

Newer gear costs $$

Newer gear has a second issue all the psu's are bespoke ie they must be a perfect match or they do not work.

the Avalon 821's do not have this issue. any 1600 watt or larger 12 volt psu should be good.

[mikeywith]

Newer gear has a second issue all the psu's are bespoke ie they must be a perfect match or they do not work.

Thank you for bringing this point up, this is a mistake that many people do, perhaps most of us has done a similar mistake, it's best to buy miners that use the same PSU and preferably the same control board, doing so allows you to have a spare of everything at a very low cost, buying say S17, T17e, Whatsminer M21s, and an S9, means you need 4 spares of PSUs and control boards, buying the same gear model you will need only 1 PSU and 1 Control board, in many cases, you might not end up using the spare because before the PSU or the control board goes bad, a few hash boards will die and then you end up with more spares.

cost is 11 x 66.54 = 731.94 for the miners. not sure if you get psu's

At $66 for that gear, I would be very interested myself, I think OP should go for it, the price is very decent compared to today's prices.