Is Bitcoin breaking up?

This presumes the blocksize limit is being fixed, which is an incorrect assumption. Originally, the proponents of Classic wanted to boost block size limits to 20MB effective January 2016 [1], and used bombastic and divisive language, inventing their own crisis even, to get people to take them seriously.

Interestingly, those same people are now contending for just 2MB, which is only 0.4MB higher than that proposed by Core.

Performance test data shows 32MB is the absolute maximum block size you can handle on a modern desktop PC today [2]. And by this I mean you could validate no more than one block per 10 minutes, hence realistically you actually couldn't run a full node on a desktop at 32MB. You'd need a clustered full node just to keep up, which is unprecedented in Bitcoin.

To make matters worse, 32MB blocks gets Bitcoin to 300 tps which is less than 1% of VISA's current capacity.

[1]: http://gavinandresen.ninja/does-more-transactions-necessaril...

[2]: https://blog.conformal.com/btcsim-simulating-the-rise-of-bit...

This narrative that Gavin and I were unwilling to compromise is deeply unfortunate. BIP 101 originally started with a 20mb limit+growth. That was based on some calculations Gavin did. At that point the Chinese miners started saying they couldn't accept 20 because of the firewall, but eight would be OK. They put announcements of their support for eight megabyte blocks in their coinbases, etc.

Why eight? Because it's a Chinese homonym for "prosper" or "wealth":

https://en.wikipedia.org/wiki/Numbers_in_Chinese_culture#Eig...

It crops up in the Chinese Bitcoin community all the time. So this choice obviously wasn't based on any kind of scientific analysis. Having Bitcoin protocol constants be decided by rhymes would obviously have been an embarrassment, but nonetheless, we compromised and did it.

After Core rejected the now-modified BIP 101, Gavin and I released XT together. At this point the miners changed their tune. They announced they would never run anything except Core, period, end of story. This "requirement" had not been specified before. From both speaking to them personally (I have had various phone calls with miners around the world, including miners in China) and their public statments, they made it clear that their loyalty to Core was absolute and no matter what changes we made to XT, they would never run it. Thus compromising further was pointless.

Why is Classic different? It wasn't, just one or two days ago. After I released my article, I was CCd on a private thread where KnC Miner published an "open letter" and suggested switching to Classic. The other miners shot him down immediately saying they wanted the change to come from Core. Then the price started sliding, and they started reversing their positions. Suddenly, Classic was acceptable whereas just hours before it had not been.

Every "version" is pure w.r.t its current rules. Hard-forking is something that impacts a new chain. The old chain still exists even after a hard-fork.

_Anyone_ can run old Bitcoin versions and participate on the old chains using the pre-hard-forked-changed rules.

There is no way to "turn off" the previous chain, at least not in the protocol.

The old version could become unmaintained, have no remaining miners, no remaining validating nodes, etc. That's true. But for this to be the case, there would have to be universal disinterest in maintaining the previous tech, or mining with the previous rules, operating and running fully-validating nodes, etc. Universal disinterest cannot be measured.

I cannot offer you any justification I agree with for the previous hard-forks. At the time that those hard-forks were deployed, various justifications were given, and as of 2016 I am not sure that I can agree with those reasons now. Perhaps at the time I would have found merit in the idea that the Bitcoin ecosystem was small enough to tolerate a hard-fork or something. Another possible rationalization is that, at the time, the Bitcoin software was horribly inefficient in hundreds of ways, this is why verification took >10 hours of a blockchain that was less than 30% the size of the current 2016 blockchain.... and 32MB was probably a security hole that everyone at the time was able to universally agree must be plugged. This sort of reasoning resonates with me even as of 2016; if there was a hole that bad in modern Bitcoin, heck yeah we would all have to do a hard-fork, it's unfortunate but security is important and I like avoiding holes.

FWIW, I don't care about purity.

Here is some text on validation costs:

http://diyhpl.us/wiki/transcripts/scalingbitcoin/validation-...

http://diyhpl.us/wiki/transcripts/scalingbitcoin/hong-kong/v...

> other releases that required a hard fork as well the world didn't end

Bitcoin isn't going to destroy the world, nsh is. Anyone saying otherwise is just trolling you.

Hearn mentions the backstory behind this in a comment here [0], posted a little while after you posted your comment. After reading his comment, does the shift from 20MB max blocks to something smaller become less "interesting" and more understandable? If not, why not?

Edit: Additionally, do you have anything to say about this comment? [1]

[0] https://news.ycombinator.com/item?id=10921219

[1] https://news.ycombinator.com/item?id=10921209