<p>Core. Bram Cohen has a good writeup on medium</p>

<blockquote>
  <p>The upcoming ‘crisis’ which is being used as a justification for a
  hard fork is something which it’s easy to convince people who aren’t
  very familiar with the technology will be a disaster. There’s a hard
  limit on the rate which transactions can happen, about five per
  second, and the transaction rate in bitcoin has been approaching that
  over time. We’re going to hit a wall! The sky is falling!</p>
  
  <p>So what happens when that limit is reached?</p>
  
  <p>Transaction fees go up.</p>
  
  <p>Literally, that’s all that happens. That’s the big ‘crisis’. What’s
  being claimed is: Transaction fees might go above two cents! The sky
  is falling! I am not exaggerating.</p>
</blockquote>

<p>and </p>

<blockquote>
  <p>Raising the block size limit is the idea of Gavin Andresen, former
  Bitcoin lead developer, who initially went around to core developers
  and players in the Bitcoin ecosystem trying to convince them that it
  should be done. The core developers had reactions ranging from neutral
  to vitriolically against it. Rather than accept this strongly negative
  reaction as a sign that his idea is a bad one, or attempting to work
  on some kind of compromise proposal, Gavin’s now blaming the arguing
  on a lack of benevolent dictator or clear voting process. There are
  several obvious problems with this. In projects which have a real
  Benevolent Dictator For Life, that person was the one who created the
  project. Gavin didn’t invent Bitcoin. He isn’t even a Bitcoin
  developer any more. He resigned his position as lead developer a year
  ago, and has been largely inactive since. Using a voting process, or
  even a system of rough consensus among core developers would cause his
  proposal to be quickly rejected. It’s only the exertion of outside
  political force which has forced it to be taken seriously.</p>
</blockquote>

CC BY-SA 3.0
2015-06-22T17:08:52.223Z
This is a political statement which doesn't answer the question.
morsecoder
CC BY-SA 3.0
2015-06-22T20:37:50.840Z
But I'll bite. What's more central to the value proposition of bitcoin? An artificial consensus limit of 1 MB that pretty much everyone agrees will need to be removed eventually, or bitcoin as a **low-cost** payment rails? Fees will go up, sure, but the fact that that happens means that other transactions with lower fees are being pushed out. This means that if we leave the 1 MB limit in place, then for many users, bitcoin simply won't work, or will be too expensive. Such a scenario is not good for bitcoin adoption.
morsecoder
CC BY-SA 3.0
2015-06-23T02:41:52.653Z
@StephenM347 I disagree - this is kind of a "vi or emacs" question where neither is objectively better. I agree with the other points.
Nick ODell
CC BY-SA 3.0
2015-06-25T14:42:00.560Z
Gavin is not a problem, miner's greed is a real problem. If XT will erase miners ability to ask more comissions and keep block size limit enough then I will support XT
qpaycm
CC BY-SA 3.0
2015-06-25T21:46:43.190Z
We are talking about the difference between USD $0.02 and USD $0.08. That is all.  In the end of May and again this past Monday, stress tests were performed.  Even at the peak, if you paid a whole dime in transaction fees, you were getting your transaction in the next block.  The backlog of transactions cleared reasonably quickly.  Bitcoin offers extremely inexpensive transactions.  It doesn't promise free and fast.
Jonathan
CC BY-SA 3.0
2015-06-25T23:19:35.830Z
first look for fees at the end of 2016 if block size limit don't change then you might be interested in how many transactions per day were at the last bubble. question you should ask yourself is - how many transactions per second Bitcoin should offer at the end of 2016?
qpaycm
CC BY-SA 3.0
2015-08-18T20:56:50.143Z
"Transaction fees go up." but that is all the problem I am trying to avoid when supporting Bitcoin TX. If miners want transaction fees to rise, its simple: don't include cheap transactions. It should not have to have anything to do with the block size limit.
lvella
CC BY-SA 3.0
2015-08-27T10:57:03.090Z
are we really talking about $0.02 to $0.08 increase?
user568021
CC BY-SA 3.0
2015-08-30T01:59:19.997Z
@user568021 Not necessarily. If everyone sends transactions at the same rate as before, even if the cost goes up a little bit, the cost will have to go way up. **The fee will have to go up enough that enough people quit sending transactions to keep the block size at 1MB.**
BenjiWiebe
CC BY-SA 3.0
2015-10-28T10:17:13.747Z
@Jonathan: No, we are not only talking about the fees rising, ultimately we are talking about making transactions prohibitively expensive to push the less important off the network due to limited throughput.
Murch
CC BY-SA 3.0
2015-06-22T16:50:10.183Z
2015-06-22T16:50:10.183Z
Jonathan
<p>The two pieces of software, Bitcoin Core and Bitcoin-XT, are very similar. Bitcoin-XT is actually just a fork of Bitcoin Core with some features added that Bitcoin Core developers didn't deem appropriate, such as a larger block size (<a href="https://github.com/gavinandresen/bips/blob/fd99a8ce04dbad96fb275e0300a7ee669e70f418/bip-0101.mediawiki" rel="noreferrer">BIP 101</a>) and relaying of double spends.</p>
<p>Bitcoin Core is more up-to-date with all of the work that the community doing. Additionally, Bitcoin-XT now has a different consensus protocol regarding the maximum size of blocks. There has been much debate within the bitcoin community about if/how/when to increase the artificially imposed block size limit (of 1 MB), and one attempt to resolve this debate is being done through Bitcoin-XT.</p>
<p>The <a href="https://github.com/bitcoinxt/bitcoinxt" rel="noreferrer">Bitcoin-XT README.md</a> has these notes on how it is different than Bitcoin Core:</p>
<blockquote>
<ol>
<li><p>Support for larger blocks. XT has support for BIP 101 by Gavin Andresen, which schedules an increase from the one megabyte limit Bitcoin is now hitting.</p>
</li>
<li><p>Relaying of double spends. Bitcoin Core will simply drop unconfirmed transactions that double spend other unconfirmed transactions, forcing merchants who want to know about them to connect to thousands of nodes in the hope of spotting them. This is unreliable, wastes resources and isn't feasible on mobile devices. Bitcoin XT incorporates work by Tom Harding and Gavin Andresen that relays the first observed double spend of a transaction. Additionally, it will highlight it in red in the user interface. Other wallets also have the opportunity to use the new information to alert the user that there is a fraud attempt against them.</p>
</li>
<li><p>Support for querying the UTXO set given an outpoint. This is useful for apps that use partial transactions, such as the Lighthouse crowdfunding app. The feature allows a client to check that a partial SIGHASH_ANYONECANPAY transaction is correctly signed and by querying multiple nodes, build up some confidence that the output is not already spent.</p>
</li>
<li><p>DNS seed changes: bitseed.xf2.org is removed as it no longer works, and seeds from Addy Yeow and Mike Hearn are (re)added to increase seed diversity and redundancy.</p>
</li>
</ol>
</blockquote>
<p>So, if you support these changes and/or the possible future changes on the consensus-block-size-limit, run Bitcoin-XT. The releases are available here: <a href="https://github.com/bitcoinxt/bitcoinxt/releases" rel="noreferrer">https://github.com/bitcoinxt/bitcoinxt/releases</a></p>

CC BY-SA 3.0
2015-08-15T20:56:03.273Z
Seems that Satoshi Nakamoto - or someone *claiming* to be Satoshi - is in deeply disagreement with the XT fork http://lists.linuxfoundation.org/pipermail/bitcoin-dev/2015-August/010238.html
Gui Ambros
CC BY-SA 3.0
2015-08-16T03:29:27.130Z
I highly doubt that email is from the real Satoshi Nakamoto. No PGP signature, and it honestly doesn't sound much like his other writings. Sounds more like a dump of the arguments others have already made. I think if Satoshi did give a response, it would include something more original.
morsecoder
CC BY-SA 3.0
2015-08-17T07:41:27.827Z
yes that sad attempt at a fake rebuttal only validates the fork and explains the reason behind it - to get whole community participating in the decisions on bitcoin future, not 3 devs.
kibitzer
CC BY-SA 3.0
2015-08-17T19:38:13.547Z
Down-voters of a perfectly unbiased answer like this are users who would rather information like this be censored away from the public. To that down-voter, you are not fully grasping the most fundamental principle that Bitcoin is built upon: decentralization.
morsecoder
CC BY-SA 3.0
2015-08-17T21:37:29.573Z
in my opinion Bitcoin is a protocol. if you create a protocol with different rules (such that it accepts different block sizes) then you're using a slightly different version of the protocol and therefore are not really using Bitcoin. it's like saying, "if you want to see my website correctly you have to download this slightly different web-browser that renders JSON instead of HTML". sure you can do that, but you're not really using the web then. you're using another web that renders JSON instead of HTML.
Luca Matteis
CC BY-SA 3.0
2015-08-17T22:06:39.733Z
@LucaMatteis, it's fine to take that point of view, but it's all besides the point, with respect to my previous comment. Just because you personally don't support a 'Bitcoin' that has larger block sizes doesn't mean this information shouldn't be available to those that do.
morsecoder
CC BY-SA 3.0
2015-08-18T17:26:58.730Z
@LucaMatteis web-browser does not render JSON ane even HTML. They just can parse them ;)
Sebastian Xawery Wiśniowiecki
CC BY-SA 3.0
2015-06-22T17:13:50.800Z
2015-08-18T21:43:48.400Z
2020-06-16T11:10:03.350Z
morsecoder
<p>I just read about Bitcoin Core and Bitcoin-XT, and I want to know what is the difference between Bitcoin Core and Bitcoin-XT?</p>

<p>And which is better Bitcoin Core or Bitcoin-XT?</p>

<bitcoin-core><bitcoin-xt>
Should I be running Bitcoin Core or Bitcoin-XT?
Fery Jhie
# Should I be running Bitcoin Core or Bitcoin-XT?

(Asked by: username_0 on 2015-06-22)

I just read about Bitcoin Core and Bitcoin-XT, and I want to know what is the difference between Bitcoin Core and Bitcoin-XT?

And which is better Bitcoin Core or Bitcoin-XT?

**Tags:** bitcoin-core, bitcoin-xt


---

## 2 answers

### Answer by username_2 on 2015-06-22. Score: 24 | Accepted answer

The two pieces of software, Bitcoin Core and Bitcoin-XT, are very similar. Bitcoin-XT is actually just a fork of Bitcoin Core with some features added that Bitcoin Core developers didn't deem appropriate, such as a larger block size ([BIP 101](https://github.com/gavinandresen/bips/blob/fd99a8ce04dbad96fb275e0300a7ee669e70f418/bip-0101.mediawiki)) and relaying of double spends.

Bitcoin Core is more up-to-date with all of the work that the community doing. Additionally, Bitcoin-XT now has a different consensus protocol regarding the maximum size of blocks. There has been much debate within the bitcoin community about if/how/when to increase the artificially imposed block size limit (of 1 MB), and one attempt to resolve this debate is being done through Bitcoin-XT.

The [Bitcoin-XT README.md](https://github.com/bitcoinxt/bitcoinxt) has these notes on how it is different than Bitcoin Core:

> 1. Support for larger blocks. XT has support for BIP 101 by Gavin Andresen, which schedules an increase from the one megabyte limit Bitcoin is now hitting.
> 2. Relaying of double spends. Bitcoin Core will simply drop unconfirmed transactions that double spend other unconfirmed transactions, forcing merchants who want to know about them to connect to thousands of nodes in the hope of spotting them. This is unreliable, wastes resources and isn't feasible on mobile devices. Bitcoin XT incorporates work by Tom Harding and Gavin Andresen that relays the first observed double spend of a transaction. Additionally, it will highlight it in red in the user interface. Other wallets also have the opportunity to use the new information to alert the user that there is a fraud attempt against them.
> 3. Support for querying the UTXO set given an outpoint. This is useful for apps that use partial transactions, such as the Lighthouse crowdfunding app. The feature allows a client to check that a partial SIGHASH\_ANYONECANPAY transaction is correctly signed and by querying multiple nodes, build up some confidence that the output is not already spent.
> 4. DNS seed changes: bitseed.xf2.org is removed as it no longer works, and seeds from Addy Yeow and Mike Hearn are (re)added to increase seed diversity and redundancy.

So, if you support these changes and/or the possible future changes on the consensus-block-size-limit, run Bitcoin-XT. The releases are available here: <https://github.com/bitcoinxt/bitcoinxt/releases>

> **Comments:**
> **username_9**: Seems that Satoshi Nakamoto - or someone *claiming* to be Satoshi - is in deeply disagreement with the XT fork http://lists.linuxfoundation.org/pipermail/bitcoin-dev/2015-August/010238.html  
> **username_2**: I highly doubt that email is from the real Satoshi Nakamoto. No PGP signature, and it honestly doesn't sound much like his other writings. Sounds more like a dump of the arguments others have already made. I think if Satoshi did give a response, it would include something more original.  
> **username_10**: yes that sad attempt at a fake rebuttal only validates the fork and explains the reason behind it - to get whole community participating in the decisions on bitcoin future, not 3 devs.  
> **username_2**: Down-voters of a perfectly unbiased answer like this are users who would rather information like this be censored away from the public. To that down-voter, you are not fully grasping the most fundamental principle that Bitcoin is built upon: decentralization.  
> **username_11**: in my opinion Bitcoin is a protocol. if you create a protocol with different rules (such that it accepts different block sizes) then you're using a slightly different version of the protocol and therefore are not really using Bitcoin. it's like saying, "if you want to see my website correctly you have to download this slightly different web-browser that renders JSON instead of HTML". sure you can do that, but you're not really using the web then. you're using another web that renders JSON instead of HTML.  
> **username_2**: @username_11, it's fine to take that point of view, but it's all besides the point, with respect to my previous comment. Just because you personally don't support a 'Bitcoin' that has larger block sizes doesn't mean this information shouldn't be available to those that do.  
> **username_12**: @username_11 web-browser does not render JSON ane even HTML. They just can parse them ;)  

---

### Answer by username_1 on 2015-06-22. Score: -5

Core. Bram Cohen has a good writeup on medium

> The upcoming ‘crisis’ which is being used as a justification for a
> hard fork is something which it’s easy to convince people who aren’t
> very familiar with the technology will be a disaster. There’s a hard
> limit on the rate which transactions can happen, about five per
> second, and the transaction rate in bitcoin has been approaching that
> over time. We’re going to hit a wall! The sky is falling!
>
> So what happens when that limit is reached?
>
> Transaction fees go up.
>
> Literally, that’s all that happens. That’s the big ‘crisis’. What’s
> being claimed is: Transaction fees might go above two cents! The sky
> is falling! I am not exaggerating.

and

> Raising the block size limit is the idea of Gavin Andresen, former
> Bitcoin lead developer, who initially went around to core developers
> and players in the Bitcoin ecosystem trying to convince them that it
> should be done. The core developers had reactions ranging from neutral
> to vitriolically against it. Rather than accept this strongly negative
> reaction as a sign that his idea is a bad one, or attempting to work
> on some kind of compromise proposal, Gavin’s now blaming the arguing
> on a lack of benevolent dictator or clear voting process. There are
> several obvious problems with this. In projects which have a real
> Benevolent Dictator For Life, that person was the one who created the
> project. Gavin didn’t invent Bitcoin. He isn’t even a Bitcoin
> developer any more. He resigned his position as lead developer a year
> ago, and has been largely inactive since. Using a voting process, or
> even a system of rough consensus among core developers would cause his
> proposal to be quickly rejected. It’s only the exertion of outside
> political force which has forced it to be taken seriously.

> **Comments:**
> **username_2**: This is a political statement which doesn't answer the question.  
> **username_2**: But I'll bite. What's more central to the value proposition of bitcoin? An artificial consensus limit of 1 MB that pretty much everyone agrees will need to be removed eventually, or bitcoin as a **low-cost** payment rails? Fees will go up, sure, but the fact that that happens means that other transactions with lower fees are being pushed out. This means that if we leave the 1 MB limit in place, then for many users, bitcoin simply won't work, or will be too expensive. Such a scenario is not good for bitcoin adoption.  
> **username_3**: @StephenM347 I disagree - this is kind of a "vi or emacs" question where neither is objectively better. I agree with the other points.  
> **username_4**: Gavin is not a problem, miner's greed is a real problem. If XT will erase miners ability to ask more comissions and keep block size limit enough then I will support XT  
> **username_1**: We are talking about the difference between USD $0.02 and USD $0.08. That is all.  In the end of May and again this past Monday, stress tests were performed.  Even at the peak, if you paid a whole dime in transaction fees, you were getting your transaction in the next block.  The backlog of transactions cleared reasonably quickly.  Bitcoin offers extremely inexpensive transactions.  It doesn't promise free and fast.  
> **username_4**: first look for fees at the end of 2016 if block size limit don't change then you might be interested in how many transactions per day were at the last bubble. question you should ask yourself is - how many transactions per second Bitcoin should offer at the end of 2016?  
> **username_5**: "Transaction fees go up." but that is all the problem I am trying to avoid when supporting Bitcoin TX. If miners want transaction fees to rise, its simple: don't include cheap transactions. It should not have to have anything to do with the block size limit.  
> **username_6**: are we really talking about $0.02 to $0.08 increase?  
> **username_7**: @username_6 Not necessarily. If everyone sends transactions at the same rate as before, even if the cost goes up a little bit, the cost will have to go way up. **The fee will have to go up enough that enough people quit sending transactions to keep the block size at 1MB.**  
> **username_8**: @username_1: No, we are not only talking about the fees rising, ultimately we are talking about making transactions prohibitively expensive to push the less important off the network due to limited throughput.  

---

