Bitcoin Forum

I understand that everyone is going to say not to mine and blah, blah, blah…  Anyway…

Is there a magic number regarding hash speed where you can try solo mining?  As a new person on a budget that’s just trying my hands at this, it seems like the earning are low when you join a pool.  I’ve been mining around 15gh/s for 1 day and 12 hours and I’ve earned .32USD or .000509 bitcoin (current bitcoin pricing is 620.13).

Without breaking the bank, is it even possible to make a profit once you factor in kw cost?

It's not really possible to earn much from solo mining unless you are extremely lucky it will be like winning the lottery so no there is no magic number that will guarantee results.

By mining in pool you sure get small amount of BTC but at least you get something. By going solo you may mine for years (with 15gh/s) and still getting zero.

Anyone can solo mine even if you have 1 gh/s. But it is like gambling trying to hit the jackpot. You will need to have at least 100Th/s to consider yourself not gambling..

Wrong. If something doesn't have a 100% chance of doing what it's supposed to, aka succeed, it's gambling.
It's simply probability, but he's right, if you don't have a few Terahashes, don't even bother, it isn't worth it.

Imho, you should do it. Your miner will never get you more than a few dollars, while if you solo-mine, there's a very small chance you might get 25 BTC.

Since losing these few dollars are not a huge risk, it would be worth the try.

Or you could try solo-mining Peercoin; the reward would be less big, but you're 100 times more likely to find a block, if I remember correctly.

Assuming difficulty stays at the current level 17,336,316,979 and with your 15 GH/s, you should expect to get a block in 157.4 years. :)

If you have double the hashrate, the time would be halved (again, assuming difficulty stays at the same level, which is extremely unlikely).

The blocks will yield virtually no coins quite earlier than that!

However, a block could also potentially be found in one minute, which makes it a good option for someone who wants to gamgle at very low risk (the only risk being losing the few mBTC OP would have made by mining in a pool).

It's always a gamble, but I would say about 1% of the hash at least, because every 1000 minutes you should find a block (in bitcoin) which in theory is good, but there is a 1/100 chance each block, so you could never win in your entire life, or you could find every single time. It is all about luck.

a 1% chance would be really good, considering that 144 blocks are mined every day. Even 1/1000 would still give acceptable chance of finding a block (ie. at least one per difficulty readjustment)

The total network hashrate at this moment is about 127,500 TH/s, according to blockchain.info stat https://blockchain.info/stats.
So, you would need to have 127 TH/s to have just 0.1% of network hashrate. ;D

Haha, OP would need an insane amount of luck!

Still, it's more likely than winning the lottery :P

With bitcoin difficulties exponentially growth, if you don't hit a block within a few months, the chance to hit one in the years after those window is non-existent. So pools do provide a very valuable service, they decrease the variance and therefore increase the expected value (due to rising difficulty). Without exponential growth solo mining would always be the best expected value, but that is not the case with bitcoin.

I also thought it was extremely rare to find a block... but.. I found 4 blocks since 18th July on polmine.pl (sciack) so now I decided to go solo mining on bitsolo... I hope to find at least 1 block soon...

You have found 4 blocks in the past 10 days?  How much hashrate do you have now? :o

Yes, exactly I am shocked, I lost 100BTC!!

I had 10TH/s on polmine, now I dedicated more than 4TH/s on bitsolo.net, wish me good luck!

I would say that you should have a hashrate equal to at least ~0.7% of the overall network if you wanted to try solo mining. This works out so that you would be expected to mine 1 block per day.

damn, how much hash do you need to solo/mine these days? Penta?

Nah, you just need some TH/s to get a reasonable chance (not high, but it is doable) to get a block.
sciack (in post 16) got 4 blocks in 10 days with just 10TH/s, but unfortunately he wasn't solo-mining. :)

You can actually see mining as a sort of lottery. You can solo mine with any amount, you just have to be ok with the resulting odds. The other factor however is that the price of BTC and difficulty both change to likely make your odds less and less over time. Mining pools help you follow the "bird in the hand" quote. If I were solo mining, I'd want to make sure I had a chance at getting a few blocks each difficulty period so once every 500 blocks or 0.2% or 294 TH (for 147,000 TH average hashrate today).

I have had almost 0.2% of the network before, but that was back in the early days long before ASICs.

You realistically need to earn on average a block a day or more to consider solo mining.  Look at the largest pool behind Ghash and DiscusFish - BTCGuild.  They have had 8 hour spans with no blocks found.  That's with 11 PH at one point.  Even if you had 150TH/s you could easily go an entire difficulty and not get a block - you would want to shoot yourself.  Then the difficulty would go up and it would be even harder for the next 2016 blocks.

Today, only people with large private farms consider solo mining unless you seriously love gambling.

I would surmise that having 0.5% of the total network hashrate would be enough to find at least 3 blocks a week. Luck would obviously play a huge factor, but 0.5% might be consistent enough as is. It would be much more prudent to at least have 1% though, since the network hashrate is continually increasing. Anyway, if my information is accurate, then 0.5% of the current total network hashrate would amount to over 677 Ths. That would require an investment of over a million dollars, not including electricity, maintenance and housing costs.

Guys, you do realize that it really doesn't make sense do mine with such a low hash rate you are all suggesting (<10 GH/s), the chances are so incredibly low (and are getting worse every 2 weeks) that you won't find a block. If it took you 150 years today, it will take you 1000 years this time next year. Not going to happen.

With 0.5% of total network hashrate, you should expect to find 0.5% of the future blocks and so you should get 10 blocks every 2016 blocks (usually, 12-13 days) on average. ;D

That's a theoretical estimate based on proportional percentages. I did not base my estimate on that because it is unreliable when small numbers are involved. I was surmising based on a squared-percentage principle, which from my personal perspective, provides a better estimate for real world values. Essentially, my assertion is that one's estimated found blocks are more likely to be squarely proportional to one's controlled percentage of total network hashrate rather than directly proportional. For example, having 0.1% of the total network hashrate will net you an estimated (0.1 * 0.1 = 0.01)% rather than 0.1%. Obviously, that is due to luck or lack of it. However, like I said, I find that it functions as a better estimate for real world values. It's all irrelevant anyway. Anyone who can do fourth grade math can easily calculate percentages on their own if they believe that probability is the same thing as statistics.

Yeah it's prudent to assume a certain percentage of the current total network hash rate. It doesn't take too much bad luck to find less blocks than anticipated, I think it's better to join a pool for a steadier payout. Also keep in mind, that the variance can be a major pain! You may not find a block for a multiple of the expected interval!

It all comes down to how much time you are willing to accept between paydays and how much variance.  Remember bitcoin mining is a poisson distribution ( http://stattrek.com/online-calculator/poisson.aspx ).  Lets assume you are not willing to go one difficulty period without finding a block.

If you have 1/2016th (0.05%) of the network you should find on average 1 block per difficulty period.
Expected = 1 block
Probability of 0 blocks = 36.7%
Probability of 1 bock =  26.4%
Probability of 2+ blocks = 36.7%

You have a ~1 in 3 chance of doubling (or more) your return but also a ~1 in 3 chance of earning nothing. That is probably more risk than most miners are willing to take.

If you have 2/2016th of the network (~0.1%) you should find on average 2 blocks per difficulty period.
Expected = 2 blocks
Probability of 0 blocks = 13.5%
Probability of 1 block = 27.1%
Probability of 2+ blocks = 59.4%

Looking better but lets look at 5 times as much hashrate, 10/2016th of the network (0.25%).

If you have 10/2016th of the network (~0.5%) you should find on average 10 blocks per difficulty period.
Probability of 0 blocks = ~0% (1 in 22,026)
Probability of 1 to 5 blocks = 6.7%
Probability of 6 to 9 blocks = 39.1%
Probability of 10+ blocks = 54.2%

So less than a 7% chance of earning less than half of expected.  How about a nice even 1% of the network.

If you have 20/2016th of the network (~1%) you should find on average 20 blocks per difficulty period.
Probability of <6 blocks = ~0% (1 in 13,906)
Probability of 7 to 13 blocks = 6.6%
Probability of 14 to 19 blocks = 45.9%
Probability of 20+ blocks = 52.9%

Now we are looking good.  Only 7% chance of earning less than 70% of expected.  Of course your risk tolerance will vary but the same distribution can be done at any percentage of the network.  As the difficulty growth goes down you may not necessarily care about how many blocks in each difficulty period but rather how many blocks per month since the powerbill is due each month.  There are ~4,320 blocks per month which means the probability of extremely bad or good luck over that longer period of time decreases (quite a bit).

Really? Only 1%, I figured it would've been a bit more to be already that safe in terms of variance. I guess solo mining actually is a viable option for some large mining operations. The biggest problem that remains is that you have to keep up with the pace. You have to bring new and better mining equipment online with every difficulty increase.

I just lol at the "only 1%".

You need about 1600 TH/s to have 1% of network hashrate currently, which is roughly 1600 AntMiner S2 or 530 KnC Neptune.
And exactly as you said, to keep up with the uprising difficulty and network hashrate, you will need to keep buying more and more miners to maintain the 1% "market share". :)

By my calculations, assuming a 10% rise in difficulty each period, you will need about 7.3 TH/s in order to solo mine an average of one block per year over the next year. However, you are most likely to find a block earlier than later because the longer you go without finding a block, the harder it becomes.

DaT, people are misinterpreting your post to suggest that miners can expect to earn less when they solo with smaller hashrate. The expected return is identical for any hashrate between solo'ing, and pool-mining, no matter the combined hashrate, ignoring all other factors (e.g. central pools stealing fees or just plain stealing, or latency tricks like what p2pool does to achieve lower orphan rates than anybody.)

I recognise you are trying to explain that variance in return is less with pooled mining or higher hashrate, but this is meaningful only because humans think that way because of our weird broken minds. That is, a lower variance in return, and especially a more-frequent payout, feels like it is worth more to humans just because we all know we might get hit by a bus tomorrow.

What you are doing is showing in a calculation a way for people to calculate payout schedules they are more-comfortable with.

People should recognise that mining in a pool like P2Pool which has at the moment a daily payout, can be expected over time to payout identically to higher-hashrate collectives.

You are correct.  Anyone taking what I wrote and saying the expected return is less is misinterpreting it.  The expected return is based solely on the block reward (plus average fees) and the miners share of the overall network.

Indeed, I believe a big proportion of people are indeed risk-seeking (enjoys taking risk).
Just see how many people go to Vegas or gambling sites to play those negative EV games.

Please teach me how to calculate the probability of 0, 1 and 2+ blocks per difficulty period with a certain hashrate (1Th/s for an easier example) and for the current difficulty (make it 20 bil for easier example). I have some Jupiters ready for some gambling. Thank you.

It's plain useless.

It may be, but I would like to see what are the chances that a guy with ~160Th/s finds 3 blocks in 1 day http://bitsolo.net/pool-stats/

No matter how lucky a guy can be its still consider gamble unless you have 1 PH... Pool is the way!!!

However this gamble might be worth it, instead of simply mining a few dollars worth of coins in the machine's lifetime.

4 blocks in a day :)

I don't think you need to have enough mining capacity to expect to mine 4 blocks a day to be able to viably solo mine. I would argue that the figure would be closer to between .75 and 1.25 blocks per day (expected value). Once you get closer to the lower end of this range, you will likely be much better off mining on a pool because your variance can potentially hurt your return a lot.

I quit that site just because of those statistics. It is improbable at the current difficulty. He always does that. Currently solo mining peercoin and doing great!

Forget about solo mining, forget about mining at all.

Without serious equipment and cheap electricity, its really hard to mine some coins

i will try it i think, though i tried to do other alts and most of them are unprofitable also