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Title: Growning number of large mining farm and BTC generation rate Post by: Hashminepower on September 13, 2014, 06:15:22 PM I was wondering on this, we have seen reports of big mining farm popping up once in awhile. We all know they made the difficulty jump like mad. But will this affect or shorten BTC initial end generating date ?
Title: Re: Growning number of large mining farm and BTC generation rate Post by: DannyHamilton on September 13, 2014, 08:23:20 PM I was wondering on this, we have seen reports of big mining farm popping up once in awhile. We all know they made the difficulty jump like mad. But will this affect or shorten BTC initial end generating date ? A continuously increasing amount of global hashpower will shorten the amount of time it will take to generate all the bitcoins. If the hash power ever decreases, then the amount of time it will take to generate all the bitcoins will increase. Title: Re: Growning number of large mining farm and BTC generation rate Post by: dankkk on September 13, 2014, 08:32:06 PM I was wondering on this, we have seen reports of big mining farm popping up once in awhile. We all know they made the difficulty jump like mad. But will this affect or shorten BTC initial end generating date ? Yes it will. The fact that the time between difficulty changes have almost always been less then 14 days means that it will both take less time before the next halving of the block subsidy and the time before block subsidies go away altogether. Both of these statements assume that the difficulty will not decrease in the future Title: Re: Growning number of large mining farm and BTC generation rate Post by: Meuh6879 on September 13, 2014, 08:39:32 PM But will this affect or shorten BTC initial end generating date ? No difference, bitcoin mining difficulty move to correct this fact : https://bitcoinwisdom.com/bitcoin/difficulty even if the 50% of mining product shutdown, bitcoin difficulty decrease dramaticly to correct this. Title: Re: Growning number of large mining farm and BTC generation rate Post by: dankkk on September 13, 2014, 10:27:41 PM But will this affect or shorten BTC initial end generating date ? No difference, bitcoin mining difficulty move to correct this fact : https://bitcoinwisdom.com/bitcoin/difficulty even if the 50% of mining product shutdown, bitcoin difficulty decrease dramaticly to correct this. Title: Re: Growning number of large mining farm and BTC generation rate Post by: Meuh6879 on September 13, 2014, 11:52:09 PM the change of difficulty is based of the number of blocks created ... not the time.
if mining power increase, time to change difficulty decrease. Title: Re: Growning number of large mining farm and BTC generation rate Post by: Billbags on September 14, 2014, 12:15:08 AM This is the block chain's control theory feedback loop: 60minhr∗24hrday∗7dayweek 10minblock=2016 in 2weeks Tcurrent=Tprior∗tprior/2weeks D=work/2(32)=2(256)/(Tcurrent+1)∗2(32) hashes/second≈D∗2(32)/600 The current target for the block chain is determined by a calculation, so any two clients looking at the block chain will calculate the same target. This calculation aims to adjust the target such that one block will be mined every 10 minutes, no matter how much total computing power is devoted to mining. The target changes every 2016 blocks based on the timestamps within those blocks. Why 2016? Because Satoshi decided two weeks was a good interval, and at 10 minutes per block, 2016 blocks will be mined every two weeks. When 2016 blocks take more than two weeks to mine, the target goes up to make mining easier; when they take less than two weeks, the target goes down to make mining harder. In symbols, if Tprior is the previous target and tprior is the time it took to mine 2016 blocks using that target, then the updated target Tcurrent is just. The target is typically a huge number well in excess of 2(200). Also it goes down as the total hashing power of the miners goes up. Consequently, interested people usually think in terms of the difficulty instead. Definition: The Bitcoin difficulty is the average number of nonces you have to try to find a valid block — aka. the work — divided by 2(32)(roughly 4 billion). Note that D is just a number for human consumption. It scales in direct proportion to the computational effort required for mining, so twice the difficulty means twice the effort. If we know the current difficulty D, we can estimate how fast all miners are hashing in aggregate. On average, it takes D∗2(32) hashes to find a nonce that works, and the target is selected to make that take 10 minutes. Title: Re: Growning number of large mining farm and BTC generation rate Post by: wasserman99 on September 14, 2014, 07:28:20 AM the change of difficulty is based of the number of blocks created ... not the time. The change in difficulty is based on how long it takes to mine 2016 blocks after the last time the difficulty was checked. If it takes less then two weeks to mine 2016 blocks then the difficulty will increase, and if it takes more then two weeks to mine 2016 blocks then the difficulty will decrease.if mining power increase, time to change difficulty decrease. Title: Re: Growning number of large mining farm and BTC generation rate Post by: CliveK on September 14, 2014, 07:42:41 AM No Difference - by design in the Bitcoin source code. This is the block chain's control theory feedback loop: 60minhr∗24hrday∗7dayweek 10minblock=2016 in 2weeks Tcurrent=Tprior∗tprior/2weeks D=work/2(32)=2(256)/(Tcurrent+1)∗2(32) hashes/second≈D∗2(32)/600 The current target for the block chain is determined by a calculation, so any two clients looking at the block chain will calculate the same target. This calculation aims to adjust the target such that one block will be mined every 10 minutes, no matter how much total computing power is devoted to mining. The target changes every 2016 blocks based on the timestamps within those blocks. Why 2016? Because Satoshi decided two weeks was a good interval, and at 10 minutes per block, 2016 blocks will be mined every two weeks. When 2016 blocks take more than two weeks to mine, the target goes up to make mining easier; when they take less than two weeks, the target goes down to make mining harder. In symbols, if Tprior is the previous target and tprior is the time it took to mine 2016 blocks using that target, then the updated target Tcurrent is just. The target is typically a huge number well in excess of 2(200). Also it goes down as the total hashing power of the miners goes up. Consequently, interested people usually think in terms of the difficulty instead. Definition: The Bitcoin difficulty is the average number of nonces you have to try to find a valid block — aka. the work — divided by 2(32)(roughly 4 billion). Note that D is just a number for human consumption. It scales in direct proportion to the computational effort required for mining, so twice the difficulty means twice the effort. If we know the current difficulty D, we can estimate how fast all miners are hashing in aggregate. On average, it takes D∗2(32) hashes to find a nonce that works, and the target is selected to make that take 10 minutes. I assume some of the smart answers were trying to say that it will have an impact if assuming the difficulty change happens right now today, and tomorrow you double the hash power, the 2016 blocks will be found sooner, by roughly a week before the difficulty changed to compensate for the increased hash rate, meaning that the "Revelation block" will happen 1 week sooner, assuming no other changes impacted it after this event. Title: Re: Growning number of large mining farm and BTC generation rate Post by: Thenen on September 14, 2014, 08:46:43 AM I was wondering on this, we have seen reports of big mining farm popping up once in awhile. We all know they made the difficulty jump like mad. But will this affect or shorten BTC initial end generating date ? Yes, it will shorten the btc end generating date, the difficulty was suppose to adjust every 14 days but it has been adjusting at 11-12days instead. So it shorten about 2-3 days every 2 week.. Title: Re: Growning number of large mining farm and BTC generation rate Post by: niothor on September 14, 2014, 03:41:20 PM No Difference - by design in the Bitcoin source code. False. As DannyHamilton said previous , yes bitcoins will be generated faster. http://bitcoinclock.com/ Reward-Drop ETA: 2016-08-18 21:30:50 UTC (117 weeks, 3 days, 7 hours)I think this is about as accurate as we can be, this far out. That was in May. Right now : Reward-Drop ETA: 2016-08-04 06:20:07 UTC (98 weeks, 3 days, 18 hours, 40 minutes) It means that 14 days worth of coins will be mined before their schedule. Title: Re: Growning number of large mining farm and BTC generation rate Post by: Billbags on September 14, 2014, 03:46:21 PM ^ So you are saying the math in the feedback loop from the source code is wrong?
Note: Please explain so I can understand where the math goes wrong. I'm not fully understanding what you and Danny are saying? I understand these dates were estimates, if you could show the math for the new estimates or where the original control theory went wrong. This is interesting if it did. Title: Re: Growning number of large mining farm and BTC generation rate Post by: niothor on September 14, 2014, 03:59:41 PM ^ So you are saying the math on the feedback loop from the source code is wrong? Note: Please explain so I can understand where the math goes wrong. I'm not fully understanding what you and Danny are saying? I understand these dates were estimates, if you could show the math for the new estimates. Adding hashrate continuously means that before the new difficulty adjournment blocks are generated faster and faster under 10 minutes.. With the next difficulty adjustment the blocks tend to be found again at 10 minutes but with new hash added will make them faster again till the next adjustment. The math is not wrong it just that it doesn't take into account the change in the hashrate. If for example the adjustment would happen every 10 block we won't see those huge differences. Title: Re: Growning number of large mining farm and BTC generation rate Post by: Billbags on September 14, 2014, 04:08:48 PM ^ Yes, I see what you are saying. The target in the feedback loop only changes every 2016 blocks. If an
Thanks Title: Re: Growning number of large mining farm and BTC generation rate Post by: odolvlobo on September 14, 2014, 04:36:41 PM The difficulty is adjusted only so that future blocks are produced every 10 minutes (on average). There is no compensation for the fact that previous blocks were produced too quickly or too slowly.
Consider that we are now at block 320678. If the time between each block were 10 minutes, then we should be at around block 299600, and block 320678 wasn't due until February 2015. Title: Re: Growning number of large mining farm and BTC generation rate Post by: Billbags on September 14, 2014, 05:04:51 PM ^ Ya, that's what had me with the math. I kept ignoring the time(@2016) of the target calculation. The feedback loop won't make up for the blocks/time you have gained. It will only adjust the target for the next 2016 blocks with the info it has at that specific time. That's why we are few months ahead of original estimates. Thank you for finally getting this through my thick skull.
One last Question if possible:: I guess this situation of the blocks getting solved faster because of added hashrate in between target calculations would be defined as a "disturbance" with the "input variables" of the process control loop? Or would this be an "output variable" from "MIMO" or "SISO"? What would be the proper way to classify this occurring in a process control loop? Title: Re: Growning number of large mining farm and BTC generation rate Post by: wasserman99 on September 14, 2014, 06:24:19 PM ^ Yes, I see what you are saying. The target in the feedback loop only changes every 2016 blocks. If an excessive amount of hashrate is added, there are no adjustments calculated until the 2016 is reached. This will effect the number of the blocks mined and future estimates. It isn't so much that the amount of hashrate added is excessive (although there is a limit to how much the difficulty can increase - 400% every 2016 blocks), it is that the additional hashrate is not all added at the same time. Say for example that when the difficulty changes, exactly 10% additional hashrate is added to the network then at 1008 blocks after he difficulty changes, an additional 10% of hashpower is added to the network (off of the original hashrate) (and no variances in luck and no other changes to mining power) then by 2016 blocks after the previous difficulty change, the difficulty will be 15% higher but the hashrate will be 20% higheThanks |