Date for 25 BTC per Block

[kjj]

I don't know where to post this, so here it is :

are there any concerns about something like Y2K syndrome ?

are miners supposed to change something in their code ?

will the number of btc per block be the only thing that will change ?

Everything is taken care of already by Satoshi. It's in the rules. A block with number > 210,000 giving a coinbase transaction of greater than 25 BTC will be invalid and rejected by honest miners. Afaik that's all that will change (it will not really change, the rule has been there all the time, just didn't take effect because block numbers have been < 210,000 so far.

There might theoretically be a bug, but I'm sure a lot of devs and others have checked.

Code: (main.cpp)

int64 static GetBlockValue(int nHeight, int64 nFees)
{
    int64 nSubsidy = 50 * COIN;

    // Subsidy is cut in half every 210000 blocks, which will occur approximately every 4 years
    nSubsidy >>= (nHeight / 210000);

    return nSubsidy + nFees;
}

Not many places for bugs to hide in that code.

[1714140200]

1714140200

[Atheros]

And they've tested it in Testnet.

[phelix]

I don't know where to post this, so here it is :

are there any concerns about something like Y2K syndrome ?

are miners supposed to change something in their code ?

will the number of btc per block be the only thing that will change ?

one risk is the majority of pools not adhering to the rules

[molecular]

I don't know where to post this, so here it is :

are there any concerns about something like Y2K syndrome ?

are miners supposed to change something in their code ?

will the number of btc per block be the only thing that will change ?

one risk is the majority of pools not adhering to the rules

"make block reward 100 BTC instead of 25 BTC" might something the "syndicate" could decide... bitcoin would drop to 0.0001 USD in no time, though. This is why I highly doubt a majority of pools ops would do such a stupid thing.

[scintill]

Code: (main.cpp)

int64 static GetBlockValue(int nHeight, int64 nFees)
{
    int64 nSubsidy = 50 * COIN;

    // Subsidy is cut in half every 210000 blocks, which will occur approximately every 4 years
    nSubsidy >>= (nHeight / 210000);

    return nSubsidy + nFees;
}

Not many places for bugs to hide in that code.

How about this theoretical code buried in someone else's closed-source codebase?

Code:

int getBlockReward(int height, int fees) {
    // TODO compute the real value, I'm too lazy to figure out right now
    return 50 * COIN + fees;
}

However, I think it is unlikely this was written into any implementation of consequence, with an even smaller chance of the bug surviving until the reward is halved.

[kjj]

I don't know where to post this, so here it is :

are there any concerns about something like Y2K syndrome ?

are miners supposed to change something in their code ?

will the number of btc per block be the only thing that will change ?

one risk is the majority of pools not adhering to the rules

"make block reward 100 BTC instead of 25 BTC" might something the "syndicate" could decide... bitcoin would drop to 0.0001 USD in no time, though. This is why I highly doubt a majority of pools ops would do such a stupid thing.

More importantly, the rest of the network would reject those invalid blocks.

[scintill]

"make block reward 100 BTC instead of 25 BTC" might something the "syndicate" could decide... bitcoin would drop to 0.0001 USD in no time, though. This is why I highly doubt a majority of pools ops would do such a stupid thing.

More importantly, the rest of the network would reject those invalid blocks.

I think his point was that a "syndicate" of pool ops could form a majority of the network and go rogue, forcing everyone else to either accept the changed rules or risk breaking the network due to having much less hashing power to secure it.  Right? (not that I think this is likely to happen.)

[FreeMoney]

"make block reward 100 BTC instead of 25 BTC" might something the "syndicate" could decide... bitcoin would drop to 0.0001 USD in no time, though. This is why I highly doubt a majority of pools ops would do such a stupid thing.

More importantly, the rest of the network would reject those invalid blocks.

I think his point was that a "syndicate" of pool ops could form a majority of the network and go rogue, forcing everyone else to either accept the changed rules or risk breaking the network due to having much less hashing power to secure it.  Right? (not that I think this is likely to happen.)

Miners would notice that 25 accepted, valued bitcoins are worth far far more than 100 do whatever we want accepted nowhere bitcoins so profit motivated miners will secure the valuable chain for valuable pay.

Anyone at any time can start assigning themselves 100000 'bitcoins' or 'hokeycoins' or whatever they want to call them. All that matters is that people want is real bitcoins and they don't want that crap. Break the rules and everyone knows you don't have bitocins, they know it automatically, you just get ignored.

[Stephen Gornick]

I think his point was that a "syndicate" of pool ops could form a majority of the network and go rogue, forcing everyone else to either accept the changed rules or risk breaking the network due to having much less hashing power to secure it.

The nodes following the protocol won't even relay those blocks.  So the only ones that would know about them are in this mining cartel/syndicate.   That becomes a hard fork condition and the economic majority is unlikely to accept a fork which devalues their coins.

[DeathAndTaxes]

"make block reward 100 BTC instead of 25 BTC" might something the "syndicate" could decide... bitcoin would drop to 0.0001 USD in no time, though. This is why I highly doubt a majority of pools ops would do such a stupid thing.

More importantly, the rest of the network would reject those invalid blocks.

I think his point was that a "syndicate" of pool ops could form a majority of the network and go rogue, forcing everyone else to either accept the changed rules or risk breaking the network due to having much less hashing power to secure it.  Right? (not that I think this is likely to happen.)

Miner majority has no power in that case.  

If MtGox accepts tx from 25 BTC blocks and merchants accept tx from 25 BTC blocks and FastCash4Bitcoins only pays out on tx from 25 BTC blocks, and most wallet providers only show users 25 BTC blocks and full nodes reject everything but 25 BTC blocks, then the 100 BTC blocks won't have any value.

Now what would suddenly be very profitable would be the miners who broke from the "alliance" and continued to mine 25 BTC blocks.   There is significant economic value for them and with most of the miners gone the value per MH suddenly quadrupled.  

[payb.tc]

December 3rd now.    If it continues increasing, even to a lesser degree than we've been seeing recently, Block 210,000 will end up occurring in November.

 - http://bitcoinclock.com

December 2nd!

December 1st!

[molecular]

I don't know where to post this, so here it is :

are there any concerns about something like Y2K syndrome ?

are miners supposed to change something in their code ?

will the number of btc per block be the only thing that will change ?

one risk is the majority of pools not adhering to the rules

"make block reward 100 BTC instead of 25 BTC" might something the "syndicate" could decide... bitcoin would drop to 0.0001 USD in no time, though. This is why I highly doubt a majority of pools ops would do such a stupid thing.

More importantly, the rest of the network would reject those invalid blocks.

If the majority of pool-ops implement the rule, they have >51% and it is irrelevant what the rest of the network thinks of it.

EDITed because of what DeathAndTaxes said above.

Miner majority has no power in that case.  

If MtGox accepts tx from 25 BTC blocks and merchants accept tx from 25 BTC blocks and FastCash4Bitcoins only pays out on tx from 25 BTC blocks, and most wallet providers only show users 25 BTC blocks and full nodes reject everything but 25 BTC blocks, then the 100 BTC blocks won't have any value.

Now what would suddenly be very profitable would be the miners who broke from the "alliance" and continued to mine 25 BTC blocks.   There is significant economic value for them and with most of the miners gone the value per MH suddenly quadrupled.  

Wow, I really didn't think this through. Thanks for pointing this out, deathandtaxes.

[phelix]

[...]

Miner majority has no power in that case.  

If MtGox accepts tx from 25 BTC blocks and merchants accept tx from 25 BTC blocks and FastCash4Bitcoins only pays out on tx from 25 BTC blocks, and most wallet providers only show users 25 BTC blocks and full nodes reject everything but 25 BTC blocks, then the 100 BTC blocks won't have any value.

Now what would suddenly be very profitable would be the miners who broke from the "alliance" and continued to mine 25 BTC blocks.   There is significant economic value for them and with most of the miners gone the value per MH suddenly quadrupled.  

Wow, I really didn't think this through. Thanks for pointing this out, deathandtaxes.

same here. Satoshi is so good. +1

[jurasofish]

The switch to 25BTC/block is gonna bring a lot of change to the network, especially considering ASIC miners will start trickling in at the same time. I started a bet http://betsofbitco.in/item?id=673 for whether the difficulty will go up or down after the switch. It's a really difficult question because the ASIC miners will bring it up, while FPGA/GPU miners will be leaving en masse. what do you reckon? Take a bet.

[HDSolar]

I am not interesting in betting on this (Bitcoin is a big enough gamble for me right now) but I would like to continue exploring this discussion more. 

Let’s assume that BFL does begin shipments by the week of November 12 or sooner.  I toss this date out as a reasonable guess because of allot of real world factors that will force them to do something on or before this date.  Now they plan to offer a systematic approach to delivery that will take them out to the end of December to get all pre-orders out.  That is significant amount of equipment hitting the street in a short amount of time.  This act alone will cause difficulty to go up one would think.  Also keep in mind that many BFL equipment users now will need to ship their equipment back so we could see all kinds of volume changes for about a month or so. 

Now this post has listed December 2nd as the proposed day we go from 50 to 25 so that should or could cause difficulty to go down due to smaller operations dropping off. 

These two acts alone should not cancel each other out because the proposed BFL ASIC product is so significant that difficulty will jump even as large numbers of folks go to other currencies to use their equipment.

Other ASIC solutions will come online cause the difficulty to rise but not too much since the masses have purchased BFL and will not be cash positive to explore investing in other equipment.   Late comers will consider the alternatives for many reasons so their products will come online after the New Year starts.

Now the real odd question to all of this is the price per BTC.  If this jumps up higher who knows but if it drops due to fewer folks mining/using the coins this could cause a whole host of additional outcomes. 

All I can say is that starting in October to February it is going to be some wild times in this Bitcoin world. 
I would love more input to this because this is my opinion and I am trying to get as many factors ironed out as possible but one man’s point of view is what it is. 

[Stephen Gornick]

The "two week" adjustment cycles are arriving in 12.5 days, 12.7 days at this pace of growth:

Well, this last one was just over 13 days, but still enough to pull the date for block 210,000 to a November date ... November 30th!

Fortunately for GPU miners, the exchange rate has been rising too, so profitability is still pretty good:




 - https://docs.google.com/spreadsheet/ccc?key=0AmcTCtjBoRWUdHVRMHpqWUJValI1RlZiaEtCT1RrQmc

 - http://blockchain.info/charts/miners-operating-profit-margin

[Stephen Gornick]

Seals is gunna have a huge party, I don't care when it happens :-)

The even needs a name.  "Block reward adjustment day" doesn't necessarily roll off the tongue.

Some might refer to it as their GPU retirement day .. 

How about "Market Day" since we'll all be DDOSing mtgox to try and figure out what the market is doing that day.

I'm seeing the event referred to as "Halving Day".

What sucks is that the specific day isn't known ... and likely won't even be known with any degree of certainty of +/- 24 hours accuracy until maybe within a week of it happening.

[Fjordbit]

I think that the ASIC thing is kind of unfortunately timed. I would have liked to have seen what would happen if there was no transition in technology at the time. What if the halving occurred and mining was only at a 10% profit margin, suddenly putting everyone in the red by 40%? How would the market react? How would the miners react? But the conditions here are actually a little uninteresting. The price/bitcoin is so high that even a halving will keep GPUs slightly profitable, while ASICs start to roll out and will get acquired to fit into the limits of the 25 btc reward. This "First Halvings Day" will be relatively without any drama. I don't think it will give an accurate picture of what will happen when we go from 25->12.5.

[Stephen Gornick]

This "First Halvings Day" will be relatively without any drama.

You seem to be disappointed by this.

[Gyrsur]

11/30/2012