Bitcoin Forum

Each USB erupted cost about 2-2.3 bitcoins, and has 333Mh/s hash. According to calculator, it generates 0.25 BTC per month, at the current difficulty. This requires at least 8 months to beat even, with rapid diff increasing, I think people who buy USB Erupter now will never get their investment back. Any comments?

Unless they bought in bulk, or are in it for the very long term, people will most likely not make an ROI. Also, the price has already dropped on the Erupters and its going to keep dropping I suspect. This is why you see a lot of people selling off Erupters and blades, they overspent on the hardware, and now its losing value before they could make a ROI.

Even in bulk it is 1.99 BTC I think. Same conclusion. I don't see how the investment can be returned, with so many ASIC is pouring into the market.

very true. Id like to get a few myself but am opting to wait a few weeks and see where the prices are at.

I am doing the same too, the flip side is that the diff is going up quickly, because many ASICs released into the mining

If you were one of the first to receive, a ROI was just about possible. I'm also watching to see what price ASICminer set the new batches at.

yeah :(


Probably wont even be worth having an Erupter once the difficulty goes up a bit more. I wish I had the money to invest in a BFL Jalapeno or maybe a KNC miner when they come out.

I doubt they ever will.

3 to 4 months

no way. this just isn't possible at their current price and hashing rate of ~330MH/s

I believe between 1-2 years, after that you will make bitcoins. not bad as a hobby with 1 Unit :D but impractical to run serious hash with many of these units for profit

O_o

what you "believe" is completely irrelevant.

Either you can do maths or you can't, and you can't, apparently.

Well, if you believe the hashrate will stop increasing then it's relevant.
However I think it's very unlikely that this will happen. Even if the same amount of people will mine in the future, technology will advance.

Anyone who buys USB erupters now will lose out bigtime

Correct sir!

Yeah, as others have said, blockeruptors are pretty unprofitable at this point.

I'm surprised by that one video going around with the kids and the bitcoin mining farm, where they had something like 50 units of the USB model. Someone argued that if the Bitcoins they spent on them were mined long ago, then the "cost" wouldn't be that high for all the units, but the opportunity cost would still be huge...

blockerupters might be good for other stuff, but not good for mining bitcoins at current difficulty.

Isnt bitcoin increasing in difficulty sometime next year? I imagine thats when the new erupters will come out

Let's do some math:

~1 GH/s ~= 0.025 BTC per day

1/3rd of 0.025 ~= 0.0075 BTC per day per USB
0.025 * 0.30 == 0.0075

Original cost of 1 USB = 1.99 BTC, let use that figure just to be fair, as this is the lowest price you could/can get it for right now.

At the current diff, it will take each USB 266 days to reach your original investment, not including any electricity that you may have used.

diff is currently jumping 15%-28% each 10 days or so.

Depending on what your cost basis is of your bitcoin, I would say the answer to this question is a resounding no.

I seriously don't get why people are paying 2BTC + for these things.

When they drop below $50 / 0.50 BTC I may then buy a couple to add to my GPU's and send some to friends whom are on the fence about bitcoin.

15-28% each 10 days the difficulty moves up?!? Are you serious? I thought it was every 4 years.

No they won't, and this was obvious from the very beginning.

ASIC being deployed = huge jump in difficulty. Nowadays, if your miner takes more than 45 days to breakeven it will probably never pay itself back. USB miners b/e point was way more than 45 days to b/e from the very beginning, so it was obvious they wouldn't pay for themselves. They have quite an appeal as a novelty product, I would even say that conceptually its a revolutionary product, and that's what people payed for.

Hoping ROI for those was delusional, or pure ignorance.

Nope it was blind greed

The diffuculty has been going up every 1-2 weeks..

At the current hash rate, it'll take a couple of years to get back the investment.  Oh my why do we bother?

You were very mistaken. Lately difficulty is growing by 15-28% each 10 days. You can pretty much calculate that will double every month and you won't be very far off - and at least you won't be deluded by impossible ROI calculations.

Friendly advice: check network difficulty on blockchained.com and bitcoin.sipa.be and never listen to the calculations made by the folks selling the hardware, the bonds, the mining contracts, etc. They need to attract the customer and are almost always misleading as they magically forget to factor the increase in difficulty, or they consider current difficulty speaking of hardware that will be shipped or deployed in X weeks.

Just check the latest trend and do the math yourself.

It's more like 30+ % increase in difficulty per month minimum... it's just that the mining reward is decreased at 4-year intervals.
Don't make hardware decisions until you understand the dynamics at work here, in case of doubt, go to: http://www.bitcoinx.com/profit/

• raise difficulty by 45-60% to account for 4-5 weeks shipping
• reduce conversion rate by 25%
• reduce hash rate by 10%
• increase elecricity rate by 20%
• increase power consumption by 20%
• increase pofitability decline by 15%

=> check if you're still breaking even under these cirumstances (and WHEN) - adjust your numbers accordingly

PS: You are doing something wrong if you're buying erupters, you should be SELLING them !  ;D

You can be greedy but if you KNOW you will never get back your money, what's the point? I guess there are also many folks that just wanted to resell them on ebay at a profit, and some of them actually did that.

Mining is not a simple business, greed is involved too, so if you are ignorant you may get the math wrong and make an unprofitable purchase just because you didn't understood the math.

It all matters how cheap you get your electricity for.

While I won't speculate either way on whether or not these are a good buy, pointing to the likely (much) higher future difficulty is only half of the equation.

A lot of people have already made an absolute killing on bitcoin by mining when others told them they were stupid because it wasn't profitable. A few years ago, when bitcoins cost a couple pennies each, people would run the same numbers and call those that chose to mine incapable of doing basic math.

Don't forget that a lot of people are mining today based on their own assumptions about the future price of cryptocurrency. Sure, the math doesn't look great based on ~$100 per BTC, but what is you assume bitcoin goes mainstream and hits $1000/BTC in a few years? There will only ever be 21 million coins, and it bitcoin becomes say, the internet currency of choice, then $1000 per BTC is quite a low estimate.

Don't forget that the USB miners are priced in BTC. If bitcoin becomes the internet currency of choice and goes to $1,000, then you would have been better keeping the 2BTC that the USB miner costed, instead of spending them to get back 1.5BTC after 2 years. Pretty basic math.

I would say more: even if the miner is priced in fiat, I always calculate how many BTC I can buy in that moment with that amount of fiat. I decide then if I believe that the miner will generate more than that: if it's the case, I will buy the miner. If it's not the case, I will just buy the BTC.

It seems the only valid logic to me, but I read posts after posts repeating what you just wrote. I really don't get it. Buying a $200 miner when the exchange rate is 1BTC = $100 to get back 0.5BTC is a net loss in my book, regardless of the future exchange rate.

Take my advice, do not buy these you will end up losing out in the end

once you have to start thinking about low/zero electricity costs for a USB-based mining device in order to make it mine profitably, it's a fairly safe thing to say that you shouldn't be touching the whole thing in the first place. A typical computer has 4-8 usb ports, USB providing 5 volts and about 0.9-1.2 Ampere, which in turn means that we are talking about 5-7 watts per device, the BFL/Jalapeno is said to mine at 5Ghash/30 watts, i.e. 1 Ghash/6 watts. So do your own maths.

At this point i would say that if you are paying more than 300% of avalon chip costs for some hashing hardware, you probably wont be making any sizable increases in your bitcoin wallet.

on an up note, it seems that terrahash and a few others may be on the level.....   though this is still a may, well see if there klondike boards ever get up and running.

also at the rate of purchase this morning it may be to late to make money at 15 dollars per avalon chip at 300 mh/s soon

that would be fine if the usb miners were purchased in dollars

so basically what i am hearing here that Bitcoin mining is pretty much dead, unless you have TH/s miner ?

How about Litecoin?

Some people may certainly measure the cost of the device in a fiat currency. We've already established that mining back the value of the ASIC USB is nearly impossible..but if you converted, say, $200 to BTC2.0 and bought the device, then your goal would be to achieve a ROI based on what you spent in fiat as the price per BTC rises. Of course, long term investing in Bitcoin alone may achieve this..but still...mining can be fun! :D



Not necessarily true. If someone has free energy, then mining on any device (MH/s, GH/s, or TH/s) will always be profitable (until you take into account equipment wear and depreciation...though that's a whole other discussion). For the majority of us who don't have this luxury, small time mining will no longer be profitable once ASIC devices hit in full force. At that point, CPU/GPU (and maybe even FPGA) mining will probably be focused on the alternative coins, including Litecoin.

At the current price (3BT) no ROI possible for USB Block Erupter until 1 year or more.

Estimate doesn't make sense at all. It's a risky investment and it can be at $50 (or even $0.50) in a few years too.

USB erupter will never make ROI at this rate and escalating rate.
unless it's a novelty item, i'd try and sell at a loss and move on.

Those bad at math will still feel like having done a great deal then xD

well... i believe it can be used forever... unless it breaks down...

the positive part is that it consumes very little electricity...

btw... r u from sactown? coz i am too.. :P

it would be wrong anyway, since it would have been a better investiment to just buy BTC with those dollars.