Shares: 0 accepted after 12 hours of mining

[trectuse]

Alright so another question, say i got a new desktop (made in 2011), would it have a GPU included, or would i have to buy one separate.

[likuidxd]

Alright so another question, say i got a new desktop (made in 2011), would it have a GPU included, or would i have to buy one separate.

Not one off the self, at least not one that would be cost effective

58xx 59xx & 69xx series from ATI is where you want to be

[trectuse]

I am getting a new computer, because my best one is the one i am currently using, with only 1 GB of RAM, my other computer broke which had 6GB of ram, among other things (made in 2009). I was just wondering if I would be able to run bit coin on it and get decent amounts of shares, or would i have to buy a GPU to get good amounts of shares?

[likuidxd]

do you possibly know of a tutorial to install a gpu?

GPU (Graphics processing unit) is simply "better graphic card", something like ATI Radeon 5870.

Slush just hinted to you the most initially cost effective GPU on the market. You can get a used 5870 for 175-200 ad it cranks out 350-400 MHs consuming ~188W of power

[nmat]

Alright so another question, say i got a new desktop (made in 2011), would it have a GPU included, or would i have to buy one separate.

All computers have GPUs - it is typically were your monitor connects to - but you can't mine with some of them (the older ones). The best GPUs for mining are from AMD (former ATI). Take a look at this list: https://en.bitcoin.it/wiki/Mining_hardware_comparison The higher the Mhash/s the more bitcoins you will earn.

Note that you will not earn a lot of money by mining. You might actually lose money because of electricity costs. Check this calculator http://tpbitcalc.appspot.com/

[slush]

This would be true if you were solo mining with a CPU. Just to give you some figures: if you solo mine with a CPU - let's say you get around 2 MHash/s - you will have a 50% chance of finding a block in around 100 years.

Claim "you'll never find a block with a CPU" was near true on solo mining AND in times of rising difficulty; Difficulty simply went up faster than miner's probability to find a block. Now, with collapsing difficulty, this isn't an issue.

I'm not saying that you have real chance to find a block with a CPU. I'm saying that your chance is strictly proportional to provided hashrate. There isn't anything like 'skipped block'. Even if you're mining with 1 hash per second, you have still only 300000000x lower chance than mining with ATI 5870.

But the pool only pays if you submit a share and since you can't submit a share fast enough, you will not earn anything.

Again, you're partially right. With low hashrate, your chance to hit a share to every round is pretty bad. However in longer time period (for really slow hashrate maybe a week or two), you'll still get the expected payout. One round means nothing. You need to think at least in mid-term.

in real world you will simply not get paid unless your pool pays for invalid shares (and you need to tweak your client to disable long polling or something...)

And this is completely wrong :-). Slow CPU has absolutely nothing with invalid shares. And turning off long polling will make it definitely worse ;-).

You're probably mixing many things together. I recommend you to read stuff around mining and getwork interface on bitcoin.it wiki.

[trectuse]

do you possibly know of a tutorial to install a gpu?

GPU (Graphics processing unit) is simply "better graphic card", something like ATI Radeon 5870.

Slush just hinted to you the most initially cost effective GPU on the market. You can get a used 5870 for 175-200 ad it cranks out 350-400 MHs consuming ~188W of power

I wasn't looking to mine bit coins competitively, but i simply want to mine bitcoins effectively for the hardware I already own or am about to own. So basically how many MHs would a new computer today would produce (a high end computer).

[slush]

I wasn't looking to mine bit coins competitively, but i simply want to mine bitcoins effectively for the hardware I already own or am about to own. So basically how many MHs would a new computer today would produce (a high end computer).

Not buying specialized hardware is smart move (with current price) and supporting bitcoin with your existing hardware is good choice, too. Nobody can tell you how much MHs you'll have, it depends only on CPU type and frequency or GPU type. You can find stats for most used hardware on  https://en.bitcoin.it/wiki/Mining_hardware_comparison (as nmat already wrote).

[nmat]

This would be true if you were solo mining with a CPU. Just to give you some figures: if you solo mine with a CPU - let's say you get around 2 MHash/s - you will have a 50% chance of finding a block in around 100 years.

This was true in solo mining AND in times of rising difficulty; Now, with collapsing difficulty, this isn't an issue.

I'm not saying that you have real chance to find a block with a CPU. I'm saying that your chance is strictly proportional to provided hashrate. There isn't anything like 'skipped block'. Even if you're mining with 1 hash per second, you have still only 300000000x lower chance than mining with ATI 5870.

But the pool only pays if you submit a share and since you can't submit a share fast enough, you will not earn anything.

Again, you're partially right. With low hashrate, your chance to hit a share to every round is pretty bad. However in longer time period (for really slow hashrate maybe a week or two), you'll still get the expected payout. One round means nothing. You need to think at least in mid-term.

in real world you will simply not get paid unless your pool pays for invalid shares (and you need to tweak your client to disable long polling or something...)

And this is completely wrong :-). Slow CPU has absolutely nothing with invalid shares. And turning off long polling will make it definitely worse ;-).

You're probably mixing many things together. I recommend you to read stuff around mining and getwork interface on bitcoin.it wiki.

OK, you are correct I thought for a while and I realized my mistake. The reward you get by mining with a CPU is so small that you need a lot of tries until you can hit a share.

Regarding invalid shares, I will read on it, but slower systems have higher percentage of stale shares. Why is that?

[trectuse]

I wasn't looking to mine bit coins competitively, but i simply want to mine bitcoins effectively for the hardware I already own or am about to own. So basically how many MHs would a new computer today would produce (a high end computer).

Not buying specialized hardware is smart move (with current price) and supporting bitcoin with your existing hardware is good choice, too. Nobody can tell you how much MHs you'll have, it depends only on CPU type and frequency or GPU type. You can find stats for most used hardware on  https://en.bitcoin.it/wiki/Mining_hardware_comparison (as nmat already wrote).

alright, thanks! I will post again later (maybe this weekend if i have time to buy a computer) to let you know how it turns out!

[trectuse]

This would be true if you were solo mining with a CPU. Just to give you some figures: if you solo mine with a CPU - let's say you get around 2 MHash/s - you will have a 50% chance of finding a block in around 100 years.

This was true in solo mining AND in times of rising difficulty; Now, with collapsing difficulty, this isn't an issue.

I'm not saying that you have real chance to find a block with a CPU. I'm saying that your chance is strictly proportional to provided hashrate. There isn't anything like 'skipped block'. Even if you're mining with 1 hash per second, you have still only 300000000x lower chance than mining with ATI 5870.

But the pool only pays if you submit a share and since you can't submit a share fast enough, you will not earn anything.

Again, you're partially right. With low hashrate, your chance to hit a share to every round is pretty bad. However in longer time period (for really slow hashrate maybe a week or two), you'll still get the expected payout. One round means nothing. You need to think at least in mid-term.

in real world you will simply not get paid unless your pool pays for invalid shares (and you need to tweak your client to disable long polling or something...)

And this is completely wrong :-). Slow CPU has absolutely nothing with invalid shares. And turning off long polling will make it definitely worse ;-).

You're probably mixing many things together. I recommend you to read stuff around mining and getwork interface on bitcoin.it wiki.

OK, you are correct I thought for a while and I realized my mistake. The reward you get by mining with a CPU is so small that you need a lot of tries until you can hit a share.

Regarding invalid shares, I will read on it, but slower systems have higher percentage of stale shares. Why is that?

I believe it's because since the computer is so old, it has a lower Mhash/s rate, so when it is assigned a share, another much faster computer finishes its share, and is assigned the same one as you, that computer then completes the share you had and it becomes a stale share, since it would have been solved twice, the second time being you.

[nmat]

I believe it's because since the computer is so old, it has a lower Mhash/s rate, so when it is assigned a share, another much faster computer finishes its share, and is assigned the same one as you, that computer then completes the share you had and it becomes a stale share, since it would have been solved twice, the second time being you.

Shares are never the same for different computers. From what I understand, stale shares occur when you send your share after a block has been solved (so it is no longer valid). Long polling allows the pool to notify the miners when a block is solved so that they can start working on a new share.

[trectuse]

I believe it's because since the computer is so old, it has a lower Mhash/s rate, so when it is assigned a share, another much faster computer finishes its share, and is assigned the same one as you, that computer then completes the share you had and it becomes a stale share, since it would have been solved twice, the second time being you.

Shares are never the same for different computers. From what I understand, stale shares occur when you send your share after a block has been solved (so it is no longer valid). Long polling allows the pool to notify the miners when a block is solved so that they can start working on a new share.

Ah, I must have read the wikipedia article wrong.

[slush]

Shares Jobs are never the same for different computers. From what I understand, stale shares occur when you send your share after a block has been solved (so it is no longer valid). Long polling allows the pool to notify the miners when a block is solved so that they can start working on a new share.

You're correct, stale share means that computer was working on job which was created from previous block (miner need actual data as fast as possible, that's also reason for implementing long polling). There's no reason for a relation between hashrate and stale rate, which also fits my observation while testing my pool on slow miners.

Just a small correction in terminology. "Job" is something what server gives to miner to work on, it's result of "getwork" request (as you can read on wiki). Share is result of mining, it's short string sent back to pool server or bitcoin client. One specific job can lead to zero or more shares, but long term average is 1 share per 1 job (ok, it's simplified, there are some additional conditions). All this is about probability and you don't lose anything if you drop current job and start working on another job (for example because you received new job from LP connection). Everything what really matter is your hashrate (number of random tries per second), not number of jobs you're working on.

[odysseus654]

I guess part of the question behind "stale shares" is the question of how long it takes the miner to work through a single job.  Am I correct in understanding that a miner will work through all the possible combinations in the job it is working on before it "comes up for air" and checks to see what the next job is going to be?  If it takes more than a couple minutes to work through a job, then there's a possibility in that case that the miner might submit a share that was declared invalid minutes ago.  This would become more likely with a reduced time between blocks (10min for bitcoin) and less likely with a reduced difficulty (more likely to get an answer and abort the job early) and reduced job size (work through a single job faster).

As for GPUs, I think the biggest limitation of having them show up to miners is whether you have the necessary drivers (and card) to run arbitrary non-graphics-related programs on there.  Both ATI and nVidia have drivers (that don't come with the GPU, you need to download them separately) that are used to repurpose the shader processors or something to have them running bitcoins rather than polygons.

[Edit: read previous post]

[likuidxd]

I guess part of the question behind "stale shares" is the question of how long it takes the miner to work through a single job.  Am I correct in understanding that a miner will work through all the possible combinations in the job it is working on before it "comes up for air" and checks to see what the next job is going to be?  If it takes more than a couple minutes to work through a job, then there's a possibility in that case that the miner might submit a share that was declared invalid minutes ago.  This would become more likely with a reduced time between blocks (10min for bitcoin) and less likely with a reduced difficulty (more likely to get an answer and abort the job early) and reduced job size (work through a single job faster).

As for GPUs, I think the biggest limitation of having them show up to miners is whether you have the necessary drivers (and card) to run arbitrary non-graphics-related programs on there.  Both ATI and nVidia have drivers (that don't come with the GPU, you need to download them separately) that are used to repurpose the shader processors or something to have them running bitcoins rather than polygons.

[Edit: read previous post]

As far as I understand, please correct me if I'm wrong, the mining program requests new work as it send out work. So, if you are running a 5870 which would average 4-6 shares per minute and mining solo, running bitcoin -server, you would never submit a 'stale' share, rather an invalid share, because the gpu would never fall behind. The reason for shares being stale is because of the pool servers script failing to send new work in as fast a manner as it is received from the worker.

[deepceleron]

Let's get this out of the way: Mining on this poster's 200khash/s CPU is pointless. A three year old Q6600/2.4Ghz CPU gets about 6Mhash/s. A year old $120 ATI 5830 video card gets 340Mhash/s. As much BTC as the OP would make mining in four years, I mine in one day on two newer ATI graphics cards. I have given away as much BTC as he would make in a month as "welcome newbie" gifts before.

As far as I understand, please correct me if I'm wrong, the mining program requests new work as it send out work. So, if you are running a 5870 which would average 4-6 shares per minute and mining solo, running bitcoin -server, you would never submit a 'stale' share, rather an invalid share, because the gpu would never fall behind. The reason for shares being stale is because of the pool servers script failing to send new work in as fast a manner as it is received from the worker.

"shares" are not used in solo mining.

First you must understand mining:

The goal of mining (which gets you a reward of 50 BTC) is to find a SHA256 hash of the current Bitcoin transaction block smaller than a minimum target (a target directly related to the difficulty). Normally a SHA256 hash is a very big number, but with random luck you may find a hash that is smaller than normal. Bitcoin's central challenge to miners is to find a hash value significantly smaller than average as the problem you must solve in order to generate a block, a task that is incredibly difficult and unlikely right now. To even have a 50% chance of finding a block solution, you would have to perform 6305947565173954 hashes at the current difficulty.  It would take the original poster with his slow CPU hashing about 999 years (I didn't just make that up, that is the actual time I calculated) to even get to the "50% likely" point of finding a block.

When you mine solo, the mining software you are using connects to your local copy of Bitcoin. The local copy of Bitcoin tells the mining software what data to cryptographically hash, and the current bitcoin difficulty. The mining software starts mining away, hashing and hashing, but doesn't send any data back unless it finds a hash that meets the full difficulty. Even with a high-end set up, it may take months or years to find a block. During that time, nothing is sent back from the mining software to bitcoin indicating how much it is hashing, it just keeps asking for more work when needed.

When pool mining, the pool needs to know how much work each miner is doing. There needs to be a clever un-hackable system that shows how much hashing the miners are doing, even if they aren't finding any full-difficulty blocks, so that when a block is found, miners can earn some bitcoins for just helping.

So here is what pools do: the pool software tells the miners that the current bitcoin difficulty is 1. A difficulty 1 block solve is nicknamed a "share".

What? But the current Bitcoin difficulty is 1,400,000 or so?

The pool therefore gets sent a whole bunch of hashes that aren't really Bitcoin block solves. One of them might be though. The pool then has to check each miner's submission that met the difficulty 1 challenge and see if any of them also meet the full Bitcoin difficulty, which would solve a block and earn the pool 50 BTC. However, having all these low-difficulty block solves submitted by miners gives an accurate and difficult to counterfeit account of how much work each miner is doing - and a way to dole out the rewards. Only pools use this concept of "shares" to measure work.

For a lame seven year old CPU, even difficulty 1 is hard.

[trectuse]

Let's get this out of the way: Mining on this poster's 200khash/s CPU is pointless. A three year old Q6600/2.4Ghz CPU gets about 6Mhash/s. A year old $120 ATI 5830 video card gets 340Mhash/s. As much BTC as the OP would make mining in four years, I mine in one day on two newer ATI graphics cards. I have given away as much BTC as he would make in a month as "welcome newbie" gifts before.


For a lame seven year old CPU, even difficulty 1 is hard.

This is why I will be running the bit coin miner on a better computer, I simply wanted to try it out on the worst comp I had, but it was too slow.

[Gabi]

Alright so another question, say i got a new desktop (made in 2011), would it have a GPU included, or would i have to buy one separate.

Ok time for a little suggestion: study how computers work and how they are before going to buy a new one and trying again mining.
From what you write i think you don't know well how things works, so, before you end up spending money in something you don't need or is useless, do your homework and understand how things work

Every computer has a GPU (gpu simply mean graphic processor unit), otherwise you would see nothing on monitor. But that doesn't mean it support OpenCL or something else.

And, as others said, 0.28mhash/s is pretty useless when a common graphic card can make 300mhash/s or more...

A three year old Q6600/2.4Ghz CPU gets about 6Mhash/s

I have to fix you. My Q9550 make 20mhash/s. I suppose a Q6600 would make like 15mhash/s or so.

[trectuse]

Alright so another question, say i got a new desktop (made in 2011), would it have a GPU included, or would i have to buy one separate.

Ok time for a little suggestion: study how computers work and how they are before going to buy a new one and trying again mining.
From what you write i think you don't know well how things works, so, before you end up spending money in something you don't need or is useless, do your homework and understand how things work

Every computer has a GPU (gpu simply mean graphic processor unit), otherwise you would see nothing on monitor. But that doesn't mean it support OpenCL or something else.

And, as others said, 0.28mhash/s is pretty useless when a common graphic card can make 300mhash/s or more...

I am getting the computer because I need a faster one, but i was simply wondering if i would need to install any extra hardware on it to mine fast.