Bitcoin Forum

Hi, Have been browsing the forums and learnt alot about bitcoins here.

So, firstly, I would like to thank everyone who shares their experiences in this forum, and also you, who is reading this  :)

Second, I am thinking of purchasing some miners, Avalon A6 or antminer S7.

Wondering if it would be better to purchasing new ones, or would it be better off purchasing used ones? Also, where should i go searching for used miners?

I have recently read about BitFury's new chips, and some speculated that it would reach end users by Q2 2016. Should i be waiting, or should i purchase some miners right now?

Thirdly, I visited a mining farm of my friend's. I was thinking of installing air conditioning in my farm but he shared with me that he used to do that. but now, he simply suck out the hot air using exhaust fan. Can i ask for some opinions on cooling?

Thanks for all the help!

PS: I'm running on very cheap electricity, almost negligible to our costs.

Right now you are better off purchasing new miners since new miners come with warranty and are cheaper then that is on the used market.

Thanks for the recommendation.

Why am i considering used miners?

Our ROI is basically Earnings/$$ used to buy hardware. Since our electricity costs are negligible, our only costs is the initial cost for the hardware. Thus, it would be best for us to purchase the lowest $$/TH hardware.

Also, If i'm not wrong, i believe warranty is only for first 3 months, and i've read through this forum that the miners should be working most of the time. So I'm thinking of saving costs and achieving ROI A.S.A.P instead of paying a additional premium for the warranty and being "first owner".

Am I right to think about it this way?

Yeah but like the previous user told you, the used S7's are going for the same price or higher than the new S7's. So thats something to check.

And yes you are otherwise right and also, if you buy used hardware that ran for a long time, it will probably last for a while longer. When you buy new, maybe its a bad batch.
The only thing to keep in mind is, if you buy let say 100 S1's instead of 2 S7's you're going to need a shit ton more wire, a shit ton more power cables, etc.

So paying a bit more for higher hashrate density is also worth considering in your $$/TH.

first off what country are you in?  or if in usa what state?

second how cheap is cheap power?

third how much power do you have?

fourth how much room do you have?

fifth 120 volt or 240 volt?

lastly what is you ability to handle noise?


if your power is 2 cents or less  and you have lots of room s-3's are okay  but 9   s-3s = 1 s-7

and 9 s-3's would use 3 antminer psu's

while and s-7 would use 1 antminer psu   so   if you pay 90 usd for an s-3 9 x 90 = 810 and 420 for psu's = 1230

while 1 s-7 is 1200 + 140 = 1340   that is not a lot of savings for the 9 s-3's

Here in the CIS countries sometimes old miners selling much cheaper after few months of mining. Also sometimes they changing power supplies for the more reliable, then overclocking boards to get additional hashes. So if after few months these boards didn't grilled yet - that's mean they ready checked and worth to buy... with care;-)..

All above i talking about 2-4-6 TH devices of course... not the old crap:-).

Buying a new mining rig is always better because it comes with warranty and you get directly from the seller/company so in case you get in trouble you can contact them and maybe they can fix it. But if you are in a country that should pay import tax etc, in this case maybe it should be buying a used one.

PLEASE use a calculator & some common sense sometimes in regardless of new or used miners. just don't get too excited to jump into the water.

objective is ALWAYS

LOWEST setup cost

LOWEST POWER

CHEAPEST miner (working ones)

Shortest time to achieve ROI then PROFIT !

even with warranty, EXTRA costs DOES apply such as sending the board back to manufacturer & downtime or manufacturer might even charge you EXTRA to repair the board & says it's NOT covered under warranty for various reasons.

New & Shiny does NOT always means good

Old & Dusty does NOT always mean economical

some basic math with a calc & a calm mind would help out alot.

Listen to him.  We can't answer that question for you. You have to do it yourself.  You may find that new is cheaper over used.  Maybe you find that used is cheaper depending on your overall goal (how much hash, how much profit, etc).

I bolded Phil's question's as they really are something you need.  I would also add make for sure you get correct electricity price with taxes and fees.   If you get off website and not real bill you might not get it right.

Others saying ROI math is important is very true.  The best I think is on bitwisdom: https://bitcoinwisdom.com/bitcoin/calculator it allows difficulty change which is far more realistic then ones that just do current period and times it out.

But as far as one to do it with I would go batch 8 or 9 of S7.   It is currently lowest price.  If noise is a issue then I would look at Avalon A6 there is a huge difference in noise levels.  Also S7 with server PSU's adds even more noise.   

yes but many get caught when it comes to PSU, PCIE's, Noise, Heat, prolly upgrading the wires/sockets/pdu's, DB box, CB's, so on & so forth, it just goes deeper that many that might have "missed" it.

all the listed above are EXTRA added to the "missed" cost !

cost = $ = more time needed to ROI before even mentioning PROFIT & by the time PROFIT hits = yay but it will be pretty thin by then.

but one will get a spanking brand new s7 b8/b9 whooops, sorry it might fail too as there are many reports about failure.

think couple of times, piece of paper + pen + calc helps = smart miner/investor.

ahhhh & lastly diff changes every 2 weeks or so, don't tell me you did NOT see it COMING !

home mining is tough, really tough now.

I would like to thank all of you for the experienced and helpful tips.

There's one question that i would require some advice on. I have recently read about BitFury's new chips, and some speculated that it would reach end users by Q2 2016. Should i be waiting, or should i purchase some miners right now?

Also, I am considering of buying alternative PSUs from Ebay. Should i be doing that? Or should i be buying PSUs from the manufacturer of the ASICs?

Some newbie questions too :

1) Should i be buying raspberry pi if i were to go for avalon 6 / antminer s7? I've seen that they have built in controller.
2) Would i require fast internet connection? As there will be alot of miners using the same connection.

We will be placing 10~20 units for a test, before we really go full scale on it.

-This is mostly speculative, its very hard to say, also the new gen chip might barely make it in time before the halving, which honestly throws all prevision out of whack. So you could ignore Bitfury for now and simply see if you can ROI easily before halving, even with 8%+ diff per step;
https://bitcoinwisdom.com/bitcoin/calculator

1) Maybe/No;
You can get a preflashed pi from Avalon or you can flash one yourself. S7 does not make use of raspi since as you said, they have built in controller (which is a BBB, very similar to a raspi)
2)No. Just stable good ping.

Right now I would wait for the next generation of miners.

The difficullty will make the current one go useless (in terms of getting ROI) within months.

But buying 1 or 2 used miners would be a good idea so you can learn about it.

He said very cheap electricity we really need that defined by a amount before we can give good advice.  We also don't know when next gen miners will be out for general public.   A lot say "I'm waiting on next gen" and never pull the trigger as there is always going to be a next gen.

But OP what is you price of "cheap electricity, almost negligible to our costs".  If we know that we can help much more without that it's kinda hard to help.

like i said new is NOT always good, for your viewing pleasure

https://bitcointalk.org/index.php?topic=1165628.msg13466880#msg13466880

I would advice you to buy a new Antminer.The cons of buying a used miner would be either consumption of extra electricity or getting really heated up at room temperature.However the new miner would come with warranty as well so its always a good deal.The price won't make a huge difference.

Did they try to power it with only 2 pcie cords?  I only see 2 in pictures that they cut out.  I would be interested to know if they did not follow the 3 rule.

Bitcoin did do pretty well today it's currently on a up swing as we speak... so that is nice for those holding BTC.

3rd pcie melted

3 connected

It is better to buy S7. It might still be useful after the difficulty rise and block halving. It is more efficient than old generations.

There is so many different factors like electricity price, if customs, if using 110/120 or 220/240.   It is not one size fit's all.

Some are better off with S7.  But if cheap electricity good chance a older one would be better.  They can get it cheaper and might ROI.  If they can ROI on a old one quicker that is where they should go.

But again this is very different for different people.

The difficulty has risen very fast recently, so the old inefficient miner will be out of use very soon even for cheap electricity price.

Not true though.  What about those with "free" electricity?  I'm not one lucky enough for it.  But if they have it amount paid per hash is more important then efficiency.

So again it all depends on what your situation is.  Mining is not one size fits all.

yeah but those are the inority, surely they can not support the network in the long term with the old s5, at some point is better for them to have the s7

and not because of the efficiency only, running the s7 over the s5 mean more hashpower over all because you're not limited by the watteg, you can fit more hashpower with the same wattege

people never thingk about this, but density is more important than the electricity when you reach a certain situation

If the new miners are burned properly. It is better to buy the new miners. If you do not stress the miner, it will last long.

just look around with b8 failure rates.

heh shiny miner yeah ?

there goes your $$$ & downtime.

those lucky gets replacements fairly quick, some i think over 3-4 weeks no response ?

all i can say GL.

I don't think we have a good estimate on this.  There is a thread and some who have had it.  But we really have no idea on  percent with B8 failures as we don't know how many units worked fine.   

I got a B8 for fun to see what was changed.  It's still working fine no issues.  But a downtime you are right is a big issue with difficulty jumping so much.

Either way you will lose money.
Therefore my advice would be to buy a miner for a hobby. Play with it and enjoy yourself.

The more money spend on your miner, the more money is being wasted..

The difficulty rises to fast. The most recent rise is 9.12%. That is equivalent 68P hash rise, or 14,600 S7. The next rise is expetected to be 10%. So if you do not have cheap electricity, do not mine.

The only game to get BTC now mining is get a KNC Titan *used* cheap..that is very very hard to do..they are overpriced imho on ebay etc....BUT should you be lucky in some
manner I'm making on 0.0927c (reduced winter rate elec from 13.7c kwh) electric about $484 usd after electric a month at 645mh for both..so that would be like 322.50 for a Titan

the key here is a CHEAP enough Titan or one of the 'lucky few' with cheap ass electric (like 0.03c kwh) at a real LOW electric rate YOU might be able to overpay for a Titan
and it all works out...(with btc halving and ltc traditionally following along) but with such an optimistic future for btc or ltc rise you'd be better off just buying ltc or btc imho

(not so say you should not keep your eye out....but unlikely)

as to why scrypt miner.....well using this calc

www.litecoinpool.org (http://www.litecoinpool.org)

It is all about the difficulty vs reward

BTC with all the large data halls and equip coming out...a home miner would be blown out of the water imho :)

So ....IF you could find a cheap enough Titan say....and IF you electric rates are really low like in Oregon USA......and IF you want to gamble the halving will raise prices

and hell probably IF you want to heat your house this winter (really I'm killing on gas heat savings) PERHAPS you may have a shot

but lots of dominoes in a row to fall the right way..probably better to do my new type of home mining for crypto

Attic Mining

You go to attic ...sell a bunch of crap (boring as hell....groan ..in my case probably have 5k of junk) on Ebay...buy BTC and LTC

then you have an empty attic (yea!) you know fix it up (in my case about 2k) into REC ROOM ......increase value of house by say 15k (big ass attic..somewhat finished)

but damn boring let me tell you :)

anyway imho where folk are at now ....

oh one other thought....you have a cubicle at work and your feet get cold...you could use the asic there to heat your toes in the cubicle..I've heard of that done on the
threads....... :)

It's not 100 percent either way there are so many individual variables.  You can't say all will lose or win on ROI.  A lot has to do with electricity price.  Some have very very low electricity which makes them still possible to ROI.   And some sell at right time of miner and ROI.

But it is true it's getting harder and harder to ROI.  No longer is a 3 month guaranteed ROI.

buy an old hardware don't make sense...

you wil have to invest in more electricity... and we're all worried about electricity...

so, buy a new model, like S7, it needs not so much electricity than 2 old miners with 1/4 less hash rate.

s7 is very cool.. you must test.

 8)

yeah if your elec rate works that is great...for me at 13.7c kwh and 0.0927c kwh (lower elec in winter) well ..(again you should just buy crypto ltc or btc)

BUT

if you really want to mine..used is only way to go imho and scrypt miner.....a BTC miner with my above costs would not fly ..even if I was crazy enough to

get a used Titan Scrypt unit (again priced too high)

but yeah if I lived in Oregon USA where some have 3 or 4c kwh elec...I'd be all over Ebay buying Titans and NEW equip :)

People have 'offered' to buy mine from those places often :)

but electric is king ..then again new equip ONLY has a 90 day warranty...so I'd fully agree with a 1 year warranty...90 days ...er not as big a deal used imho

(assuming whatever has run well the last 90 days) :)

Titans though I don't see as a good long term investment.  We know they are not the newest chip, just likely newest currently available to customers.

There are at least 2 batches of SFards out there mining for a private mine on Scrypt.  So you will compete with that.  Also the Titan and cube design has had a lot of people have problems it seems

Short or long term,  I can't see both as a good investment.

Most miners are way overprices (this includes the miners from our beloved Bitmaintech).

Bitmain price their miners just enough to think you have a chance to get ROI and if you are patient you will. But it will be in no scale towards the time you've spend.
It's a smart game they are playing, luckily most people see through it/them.

Even though most people know this, they will keep on buying the miners in the hope that the bitcoin price will rise. It is better to buy bitcoin directly.

Short term is not the greatest look at last 48 hours, the last 24 especially.  It is hurting on a lot of people compared to where we were at.   It is a decent loss if they bought in hen you post was compared to now.

Long term I agree it chances are will be better.  But short term is going to hurt miners as difficulty rises and price drops.  Not a fun mining environment.

I agree...he is better off getting coin imho...BUT the combo of 1) finding cheap ass Titan (I know unicorn hunting) or 2) having cheap ass electric or 3) the fact it will do LTC at
a profit due to the two factors above ..and 'supposedly' you would not get trampled as bad with the difficulty wave coming on to btc ..as a home btc miner now

that above is guite a line up to work as a home miner ..hell I'm just trying to find a cheap ass Titan CUBE but when they go for 800 bucks on ebay plus shipping that sure don't work
and my stuff has ROI'd plus :( so a full Titan would be quite the bag of the unicorn...at a price that would roi with electric and the purchase price ...indeed!

but yes your point is taken on the equip not yet available to customers in scrypt....but to tell you the truth this looks a lot like march 2015 when all them scrypt miners were
supposed to come out and LTC price and other scrypt dumped and it was all cancelled..(to my 2nd cheap titan ...figured i had till july 2015 to make LTC then doorstop)..the stuff I've seen they are trying to get IPO $$$ NOW for to build (innosilicoin and alcheminer ii) are about 512mh and 1150 watts....so imho price of LTC or ratio of LTC to BTC has to change considerably or they will just sit on hands and wait imho to release such..the price could yet starve off another run of scrypts....depending on scrypt data halls on the above..if they did release this equipment at these speeds a 350mh titan at 1250 watts would still be in the running imho ...assuming you 'had' one or/managed to trip over the unicorn scenario above and get one :)

So at 4.50 to 5 buck prices for LTC I bet we would see movement on such scrypt miners...at 3-4.50 er not so much..they will wait....also wait due to the fact at these prices would
be hard to get the IPO bucks they want first to fund this 2nd round of equip to private data halls ourside of their own...also a consideration imho

so my bet "as of this week..could change rapidly" they have thrown up their hands and put everything on hold ..due to btc and ltc prices dumping with all the FUD

at best a month behind at worse ...well hell ....could still be just Titans out there at the top end ..thou doubtful :)

Thanks for all the replies and sharing of knowledge.

I suppose that we will be going for antminer S7 as we feel that it would be better off buying new machines.

Just another note : We had an discussion whether to mine BTC or LTC, and we decided to go for BTC as we did not have the confidence in LTC.

Would love to hear comments from you guys.

EDIT: If we are not mistaken, scrypt miners are not readily available, as most of the companies are hoarding them for own usage. Is that right?

The scrypt ASIC miners are manufactured by 1 or 2 producers. Most of miners are used by themselves. I used to mine, but not any more.

Please do not buy any miners unless you are going to design a mining farms (Cost lots a mount of money).
Try to buy ,trade BTC for ALT. Thanks

Like hash72 said.

Don't buy any miners. The price is too high, while the difficulty will prevent you from making profit.
Either buy bitcoins directly or don't. Mining is dead.. for over a year now.

Mining is bad for high electricity price users. If your electricity is more than $0.2/kWh, it is better not to mine. Just buy/hold/use bitcoin.

I think your electicity price is more then what most should do.  At 20 cent's I would not mine on it just to high long term.  Only chance is to mine then sell gear pretty quickly.

I would really want 10 cents or less on electricity before attempting to mine.  And that is including all fee's and taxes.

For home miner, if the electricity price is less than 0.05/kwh, it is profitable to mine even after the halving.

It would depend on the miner efficiency I think once having.  No way do I see say like 1T A1's still being profitable at .05 after having, unless there is a huge bump in value of btc.

With gear being so different you can't really make blanket statements like that.

with the present rate of increase of the difficulty, the S7 will not be profitable after halving.

If true "free" users will have a heck of a lot of nice gear to run.  We don't know what difficulty will be like at having.   And just as important we don't know BTC price.

Your forgetting BTC price does play a part in mining.  We can hope it goes up, it is in no way guaranteed.  So I still think blanket statement's for most part are hard to do in mining, to many factors. 

I hate to say it and to be honest but the era of mining bitcoin is basically kind of over unless you have ridiculous amounts of money to spend to increase hash power after the difficulty. You should be aware that if you mine, at some point and time, your equipment won't secure you a decent rate of return on your investment. If you do mine, you should take into account the raising difficulty and the amount of money you can make on your equipment.

At that point is when you sell your gear to someone with lower electricity or "free" electricity.   The hope is the amount you mined + sell price is more then the miner and electricity spent.

Selling has become more and more common it seems.  I think mining will continue for those who enjoy it.  But if your looking for a get rich quick scheme mining is not that.   It is becoming longer and longer time to ROI.  I remember 3 month ROI on GPU's back a long time ago.  Mining evolves we will see that continuing.

Sadly this true. These days big mining companies run the mining game.
They and they online can make a profit with mining. Which means bitcoin is becoming more and more centralized.

Mining will concentrated in the cheap electricity places. So it will not be concentrated artificially. It is driven by market force.

Yes it's a free market and driven by people buying and selling as far as btc value.  Big farms have to play some part in it.  They mine and have cheap electricity and massive amounts of gear.

So you can count on them selling enough BTC to cover gear and expenses.   So I think big mines do play a factor in pricing.  But it's hard to say how much.

It the network is controlled by a group of party's then it is terrible.

@op
Don't that time is gone now. These days asic manufacturers just give you a small hope to get profit.
But in fact you won't, not in the current economic situation. Not now, not ever.

Back to the original question, the BEST option is to buy local *IF*

(1) there are current miners available, AND
(2) the price is competative.

 *OR*

 (1) you have free electric, AND
 (2) the price is reasonably competative for what the unit is.



 What you should do first though is crunch the numbers with your electric rate and see if you have a reasonable chance to achieve payback BEFORE you buy, after factoring in for Difficulty Increases, YOUR electric cost, and the block reward halfing that will happen probably in mid-July 2016.


 It's still possible for a small miner to compete in Bitcoin mining with the big boys - *IF* you are in an area with very very low cost electricity.

 The next-gen gear might change that for a while, as it will allow for years to achieve RoI since there won't be anything noticeably more efficient available for years - but if enough of the new gear gets bought and brought online fast enough, we're back to the "gotta have VERY VERY cheap electric to make a profit" issue before someone in a higher-cost electric area can achieve RoI.

Get brand new, most efficient miners available. If someone is selling his used device, it most likely means that it's becoming unprofitable.
 

But some with higher to normal buy machines and when it's unprofitable for them they sell it.  But they sell it and free to cheap can buy and still have a chance at some more time running.

Most miners I think will end up with multiple owners I think during the miner's life.

not really, maybe he has bad electricity to sustain the mining in his house, but if you have a cheaper electricity than him it can still be profitable for you

so it depend, certainly i would pay far less if it is used, not like the beginning where many were buying at even higher price than the new

Used mining gear is usually totally overpriced. You can even find 0,3GH USB block Erupters for about 25$. Offers with fair price are the minority of the second-hand market.
Of course, you can consider doing the same thing - selling your gear with the price 2-3x of it's real value, and consider this income as a part of ROI ;)

In general, recently released devices are more energy efficient and then profitable, than their predecessors. It will be ideal situation, if you could buy used miner right after introducing, for the price lower than you would pay for a new one. The longer you wait to get even recent model, the less time you have to make an ROI.

Some keep those up as collectors though.   There are some who have collected every color on block erupters for fun.   I did not do it on them but I did on compacs try to get every main version.  So I can understand the collecting for fun.

If you look at bigger miners they don't have the collectors.   Some of the bigger miners have decent price.  But price on ebay is always higher then here on forums.  So it also depends on where you are looking at.

Makes sense to me. Also, some people just want to be a part of mining community, they like the process and all things related to it - in that case profitability is not the factor to be considered. USB miners are very convenient and electricity costs are not worth mentioning, so they are ideal when you want to mine for fun ;)

When it comes to mining you got the
1) Miners who want to see profits, the business miners
2) Miners who want to be part of bitcoin and mine it, but also earn back their investment, most of us belong to this group
3) Miners who want to be part of bitcoin and can accept a little loss.
4) The group who try to be one of the above (1 and 2) and fails

Only the business miners can achieve ROI these days.
The've got better prices both for PSU/Asics + electricty

It's getting harder and harder for hobby miners, the difficulty level is biggest factor I think.  If we had 2-5 percent would be much easier.   But these 10, or even 15+ are scary.  Just look at this weeks difficulty it's scary high.

I think group 3 is pretty small.  Most that run at a loss I think sell gear at this point.  There is not a whole lot of reason to run at a loss.   They might lose a little before figuring it out.  There are some that claim they support BTC no mater what, and want decentralization.   But most can not afford this luxury of losing money  on a lot of gear.

BitFury has a new miner proposal to put 2MW miners into a container sized area. It is 12-16 PH each. So there will be no place for hobby miners in the future.

They have a rendering of it, that is far from having it.   You can make a rendering of almost anything.   But most of the big buyers I am guessing still have a data center set up.

Chances are they will not need to invest in this container, they will just need to swap old gear to new gear.  I don't see this container being a big seller.  When SP 30ish gear was new a company made containers and I think they got like 2 as proof of concept, but sales never caught on.