This exact question came up on the Bitcoin Stack Exchange once. I gave an answer here: http://bitcoin.stackexchange.com/questions/37292/whats-the-purpose-of-a-maximum-block-size/37303#37303 On Mon, Jun 1, 2015 at 2:32 PM, Jim Phillips wrote: > Ok, I understand at least some of the reason that blocks have to be kept > to a certain size. I get that blocks which are too big will be hard to > propagate by relays. Miners will have more trouble uploading the large > blocks to the network once they've found a hash. We need block size > constraints to create a fee economy for the miners. > > But these all sound to me like issues that affect some, but not others. So > it seems to me like it ought to be a configurable setting. We've already > witnessed with last week's stress test that most miners aren't even > creating 1MB blocks but are still using the software defaults of 730k. If > there are configurable limits, why does there have to be a hard limit? > Can't miners just use the configurable limit to decide what size blocks > they can afford to and are thus willing to create? They could just as > easily use that to create a fee economy. If the miners with the most > hashpower are not willing to mine blocks larger than 1 or 2 megs, then they > are able to slow down confirmations of transactions. It may take several > blocks before a miner willing to include a particular transaction finds a > block. This would actually force miners to compete with each other and find > a block size naturally instead of having it forced on them by the protocol. > Relays would be able to participate in that process by restricting the > miners ability to propagate large blocks. You know, like what happens in a > FREE MARKET economy, without burdensome regulation which can be manipulated > through politics? Isn't that what's really happening right now? Different > political factions with different agendas are fighting over how best to > regulate the Bitcoin protocol. > > I know the limit was originally put in place to prevent spamming. But that > was when we were mining with CPUs and just beginning to see the occasional > GPU which could take control over the network and maliciously spam large > blocks. But with ASIC mining now catching up to Moore's Law, that's not > really an issue anymore. No one malicious entity can really just take over > the network now without spending more money than it's worth -- and that's > just going to get truer with time as hashpower continues to grow. And it's > not like the hard limit really does anything anymore to prevent spamming. > If a spammer wants to create thousands or millions of transactions, a hard > limit on the block size isn't going to stop him.. He'll just fill up the > mempool or UTXO database instead of someone's block database.. And block > storage media is generally the cheapest storage.. I mean they could be > written to tape and be just as valid as if they're stored in DRAM. Combine > that with pruning, and block storage costs are almost a non-issue for > anyone who isn't running an archival node. > > And can't relay nodes just configure a limit on the size of blocks they > will relay? Sure they'd still need to download a big block occasionally, > but that's not really that big a deal, and they're under no obligation to > propagate it.. Even if it's a 2GB block, it'll get downloaded eventually. > It's only if it gets to the point where the average home connection is too > slow to keep up with the transaction & block flow that there's any real > issue there, and that would happen regardless of how big the blocks are. I > personally would much prefer to see hardware limits act as the bottleneck > than to introduce an artificial bottleneck into the protocol that has to be > adjusted regularly. The software and protocol are TECHNICALLY capable of > scaling to handle the world's entire transaction set. The real issue with > scaling to this size is limitations on hardware, which are regulated by > Moore's Law. Why do we need arbitrary soft limits? Why can't we allow > Bitcoin to grow naturally within the ever increasing limits of our > hardware? Is it because nobody will ever need more than 640k of RAM? > > Am I missing something here? Is there some big reason that I'm overlooking > why there has to be some hard-coded limit on the block size that affects > the entire network and creates ongoing issues in the future? > > -- > > *James G. Phillips IV* > > > *"Don't bunt. Aim out of the ball park. Aim for the company of immortals." > -- David Ogilvy* > > *This message was created with 100% recycled electrons. Please think > twice before printing.* > > > ------------------------------------------------------------------------------ > > _______________________________________________ > Bitcoin-development mailing list > Bitcoin-development@lists.sourceforge.net > https://lists.sourceforge.net/lists/listinfo/bitcoin-development > >