Maximum number of Mhash to solve a block.

jg

newbie

Activity: 21

Merit: 0

Quote from: Shadow Wizard on July 07, 2011, 03:48:05 PM

Quote from: jg on July 07, 2011, 02:37:20 PM

Also, solving a block by hand means that you need to calculate sha256(sha256(block of transactions + nonce)) where the hash conforms to the current difficulty... Keep in mind that all miners (combined) are currently trying 11197.84 GHashes/sec. It would take longer than the rest of your life to complete by hand.

sha256(sha256(block of transactions + nonce))
Can you explain exactly what that is,or where to go to find out.
And as far as longer then the rest of my life, I am quite aware. It is just I find knowing how to manually do it is understanding it.

SHA256 is a hash (or compression) function (see here).
The transactions are people sending btc to each other (signed with their private key).
A nonce is basically a random value.

Basically, a block contains a list of transactions plus a nonce. The SHA256 function is calculated twice. Once on the list of transactions + nonce and once again on the output of the first SHA hash.

The difficulty requirement is that there are a certain number of leading zeros in the output of the SHA function. Miners basically take a list of transactions, and do the above calculations, only changing the nonce each time. Eventually, someone will get lucky and find the correct nonce so that the output of the chained sha256 functions has enough leading zeros. Once that happens, that block is considered solved and work begins on the next block.

syllogyst

newbie

Activity: 10

Merit: 0

Quote from: Shadow Wizard on July 07, 2011, 03:48:05 PM

Quote from: jg on July 07, 2011, 02:37:20 PM

Also, solving a block by hand means that you need to calculate sha256(sha256(block of transactions + nonce)) where the hash conforms to the current difficulty... Keep in mind that all miners (combined) are currently trying 11197.84 GHashes/sec. It would take longer than the rest of your life to complete by hand.

sha256(sha256(block of transactions + nonce))
Can you explain exactly what that is,or where to go to find out.
And as far as longer then the rest of my life, I am quite aware. It is just I find knowing how to manually do it is understanding it.

You can find that information here: https://en.bitcoin.it/wiki/Block_hashing_algorithm

To understand how the current difficulty plays into generating a hash that solves a block, look at this page: https://en.bitcoin.it/wiki/Difficulty

You should probably look at this pdf also to understand the whole thing: http://www.bitcoin.org/bitcoin.pdf

Shadow Wizard

newbie

Activity: 7

Merit: 0

Quote from: jg on July 07, 2011, 02:37:20 PM

Also, solving a block by hand means that you need to calculate sha256(sha256(block of transactions + nonce)) where the hash conforms to the current difficulty... Keep in mind that all miners (combined) are currently trying 11197.84 GHashes/sec. It would take longer than the rest of your life to complete by hand.

sha256(sha256(block of transactions + nonce))
Can you explain exactly what that is,or where to go to find out.
And as far as longer then the rest of my life, I am quite aware. It is just I find knowing how to manually do it is understanding it.

EskimoBob

legendary

Activity: 910

Merit: 1000

Quality Printing Services by Federal Reserve Bank

And if you like to get really depressed

use this calculator http://striketeam.ath.cx/btccalc/btccalc.php to see how pointless it can be to solo mine at low rates. (do not get too depressed, it's just a bitcoin)

jg

newbie

Activity: 21

Merit: 0

Quote

I did not know that. So if I understand you correctly, although every block has a solution, it is theoretically possible (Although insanely unlikely) that a solution will never be found?
Or does this mean that I can never be given my "Own" block to solve, and there will always be others working on it even if I am solo mining, thus it is guaranteed that the block will eventually be solved, but whoever solves the block gets all the bitcoins?

Now that we have broken the ground on how this works a bit, is there a place I can go and read a bit about this more technically, but written for the average joe to understand. Basically I am not looking for the information on where a block comes from, and exactly how you go about solving it so that I could in theory, if I had nothing better to do with my time solve a block by hand. (Yes, I understand this is absurd, but if I know enough how to do it on paper, despite the fact it may take me the rest of my life to do but a single hash, or not, I will understand exactly how it works.) Its more for curiosity.

You aren't given your "own" block to solve - it just comes down to who in the network is the first to solve the next block. Once someone solves it, the entire network moves on to solving the next block.

Also, solving a block by hand means that you need to calculate sha256(sha256(block of transactions + nonce)) where the hash conforms to the current difficulty... Keep in mind that all miners (combined) are currently trying 11197.84 GHashes/sec. It would take longer than the rest of your life to complete by hand.

This may help: http://en.wikipedia.org/wiki/Bitcoin#Generation

Shadow Wizard

newbie

Activity: 7

Merit: 0

Quote from: Auspician on July 07, 2011, 09:32:04 AM

Quote from: Shadow Wizard on July 07, 2011, 12:55:40 AM

"If my computer gets an average of 250Mhash/s, what is the maximum amount of time it would take me to solve a block, and get 50 bitcoins?"

An infinite amount of time. Since your 250Mhash/s currently accounts for 1/44124th of the network, you have a 1:44124 odds of solving any particular block. However, your odds do not automatically get better with time.

To give an example of this, if you were playing a lottery that had one-in-a-million odds and you played the lottery a million times, you are not guaranteed to win even once. On the other hand, you might win twice or even more. It just depends upon luck.

If you're interested in the really complicated math you can figure out exactly your odds of solving a block on any particular day, week or month - but with your hash rate I'd suggest that if the difficulty were to stay the same (which it won't) you'd solve a block every 10 months on average.

You'd be much better off to mine with a pool, and get smaller, more regular payouts. I recommend Triple Mining as one of the best smaller pools out there; the link is in my sig.

I did not know that. So if I understand you correctly, although every block has a solution, it is theoretically possible (Although insanely unlikely) that a solution will never be found?
Or does this mean that I can never be given my "Own" block to solve, and there will always be others working on it even if I am solo mining, thus it is guaranteed that the block will eventually be solved, but whoever solves the block gets all the bitcoins?

Now that we have broken the ground on how this works a bit, is there a place I can go and read a bit about this more technically, but written for the average joe to understand. Basically I am not looking for the information on where a block comes from, and exactly how you go about solving it so that I could in theory, if I had nothing better to do with my time solve a block by hand. (Yes, I understand this is absurd, but if I know enough how to do it on paper, despite the fact it may take me the rest of my life to do but a single hash, or not, I will understand exactly how it works.) Its more for curiosity.

Auspician

full member

Activity: 126

Merit: 103

Quote from: Shadow Wizard on July 07, 2011, 12:55:40 AM

"If my computer gets an average of 250Mhash/s, what is the maximum amount of time it would take me to solve a block, and get 50 bitcoins?"

An infinite amount of time. Since your 250Mhash/s currently accounts for 1/44124th of the network, you have a 1:44124 odds of solving any particular block. However, your odds do not automatically get better with time.

To give an example of this, if you were playing a lottery that had one-in-a-million odds and you played the lottery a million times, you are not guaranteed to win even once. On the other hand, you might win twice or even more. It just depends upon luck.

If you're interested in the really complicated math you can figure out exactly your odds of solving a block on any particular day, week or month - but with your hash rate I'd suggest that if the difficulty were to stay the same (which it won't) you'd solve a block every 10 months on average.

You'd be much better off to mine with a pool, and get smaller, more regular payouts. I recommend Triple Mining as one of the best smaller pools out there; the link is in my sig.

Snipa

newbie

Activity: 12

Merit: 0

Quote from: Shadow Wizard on July 07, 2011, 12:55:40 AM

This thread is not about understanding how any of this stuff works, its to answer the simple question, "If my computer gets an average of 250Mhash/s, what is the maximum amount of time it would take me to solve a block, and get 50 bitcoins?"

The answer to your question, is forever. There's no guarantee when you'll get the right block answer. As noted before, you've got an equal chance to solve it in 30 seconds, as you do 10 years from now. A better question is "How quickly can I mine to get 50 bitcoins if I'm in a pool" And that comes down to your mhash/second, at 360mhash/sec, which is what my cards are avging out at, I'm doing ~7 bitcoins/month, or just a bit over 7 months to make 50 coins. You could use that as a rough estimate for how long it would take to get a single block. As a side note, that dos'nt take into account the tremendous rise in difficulty recently, or how much harder it's going to get to mine. To be honest, I doubt single miners stand much of a chance, unless you're that guy who wins the lottery every time he goes and plays.

zebedee

donator

Activity: 668

Merit: 500

Now's when you wish you'd paid attention in probability and statistics classes....

Jaime Frontero

full member

Activity: 126

Merit: 100

yes - go here:

http://www.alloscomp.com/bitcoin/calculator.php

click on the highlighted words that say "old calculator".

plug in the difficulty level (currently at 1564057) and the kilohash/sec your miner reports. n.b., a Mh/sec = 1000Kh/s. so if you're getting 250Mh/s, you'd put in 250000.

click 'calculate'.

this is why we mine in pools...

Shadow Wizard

newbie

Activity: 7

Merit: 0

Please keep in mind I am very new to this.
Lets assume solo mining.
To 'dumb it down' to my understanding when you mine bitcoins are you given a mathematical problem to solve, and exactly when you come up with the answer is a bit random. You could solve the problem within seconds, or you could try every single possible combination, and only hit the correct answer on the last possible 'guess' This would be the least amount of Mhash's VS the most amount needed.
So here is the question. Is there a place I can go to find out, and what are currently the maximum amount of hashes required to solve a block?

This thread is not about understanding how any of this stuff works, its to answer the simple question, "If my computer gets an average of 250Mhash/s, what is the maximum amount of time it would take me to solve a block, and get 50 bitcoins?"

Topic: Maximum number of Mhash to solve a block. (Read 1498 times)