[jedunnigan]

People like to quote the scalability page and claim that Bitcoin will have no problem scaling, but I don't think they really understand what Bitcoin will look like at scale. No one is saying that it _can't_ handle howevermany txs / second. But do you want it to? That is the real question.

Right now the network has <7000 nodes, a number that has dropped from almost 30K in the past few years. [0] The blockchain is <30GB and a node can expect to handle ~15GB/day of bandwidth. [1] You will also need at least a gig of RAM, preferably more. The UTXO is 500MB (which needs to be stored in memory).

So what we know is that despite the relatively low requirements of running a node, we are bleeding them faster than we can get new ones. People claim that storage space and bandwidth getting cheaper will solve the problem. Given past performance of the node landscape, that statement does not hold weight.

So what are the consequences of all this? Well, the node landscape will centralize very quickly as the bandwidth and storage requirements far outpace what most would be willing to provide the network gratis. Universities and large payment processors will be the only ones who can afford to run full (archival) nodes. Pruning and all that will help, sure. But in order for Bitcoin to remain true to its decentralized roots, a distributed node landscape is vital. If everyone isn't validating everyone else's transactions we have a big problem (imo, of course).

[0]https://getaddr.bitnodes.io/ [1]http://statoshi.info/#/

[cgjaro]

Yes we want it to scale, even if it means full nodes run only by large organizations. The benefits of decentralization would be very real and tangible even if only, say, 1000 organizations (companies, universities, etc) were able to host and operate Bitcoin nodes. This would still make Bitcoin clearly decentralized compared to a single company (like MasterCard) processing all your CC transactions. For example Mastercard decided of their own accord to block CC donations to Wikileaks [1] but one of these 1000 hypothetical organizations running full nodes would be unable to do such a thing and block specific transactions.

The number of full nodes decreased in large part because in the early history of Bitcoin in late 2010 or early 2011 your only option to have a secure wallet or to mine reliably was to run a full node locally. But nowadays there are many alternative lightweight clients using the SPV protocol, and a lot of reliable mining pools (it was in mid-2011 that pools started mining more coins than solo miners running full nodes). So of course many users stopped running full nodes.

[1] http://www.theregister.co.uk/2010/12/07/wikileaks_latest/

[jedunnigan]

I wasn't commenting on what is better or worse. I was simply stating that there is a tangible effect on the decentralization of the network when you have a limited number of nodes. For example, maintaining privacy becomes much harder as these nodes become major "pipelines" for fresh first hop transactions. The list goes on, but in reality it depends on how many there are, a number we can't predict. FWIW, I think your number is generous.