Quote from: runpaint on January 31, 2015, 01:36:01 AM

It's not just connection speed that will prevent normal people from running Bitcoin; the best internet service I can get at my house has a 250gb monthly limit.

Also, I'm currently running full nodes on computers with 500GB hard drives. Is that the message? "Buy bigger computers and move somewhere that offers better internet service" ?

I think we should target somebody with a "pretty good" computer and a "pretty good" home internet connection.

And assume that network bandwidth, CPU and storage will continue to grow at about the rates they've been growing for the last 30 or more years (see the wikipedia pages on Moore's Law and Nielson's Law for pointers to discussions on those).

250gb per month is plenty for a 20MB block size
(20MB every ten minutes times 6 blocks per hour times 24 hours/day times 31 days/month == 90GB; we currently transmit all transaction data twice (haven't optimized that yet), so double that and you're still well under 250gb per month).

I believe it is extremely important to maintain the fundamental properties that Satoshi laid out -- because the system he described is the system that all of us who own bitcoin bought in to.

If the collective decision is to change some of those fundamental properties, then there must be extremely good reasons to do so.

On the block size issue, Satoshi said on Sun, 02 Nov 2008 on the metz-dowd cryptography mailing list (in reply to a question about scalability):

Quote

Long before the network gets anywhere near as large as that, it would be safe for users to use Simplified Payment Verification (section Cool

to check for double spending, which only requires having the chain of block headers, or about 12KB per day. Only people trying to create new coins would need to run network nodes. At first, most users would run network nodes, but as the network grows beyond a certain point, it would be left more and more to specialists with server farms of specialized hardware. A server farm would only need to have one node on the network and the rest of the LAN connects with that one node.

The bandwidth might not be as prohibitive as you think. A typical transaction would be about 400 bytes (ECC is nicely compact). Each transaction has to be broadcast twice, so lets say 1KB per transaction. Visa processed 37 billion transactions in FY2008, or an average of 100 million transactions per day. That many transactions would take 100GB of bandwidth, or the size of 12 DVD or 2 HD quality movies, or about $18 worth of bandwidth at current prices.

If the network were to get that big, it would take several years, and by then, sending 2 HD movies over the Internet would probably not seem like a big deal.

When I first heard about Bitcoin, it was small enough I could read everything, and I did, including all of those mailing list posts. The promise of a system that could scale up to rival Visa is part of the vision that sold me on Bitcoin.

I feel bad suggesting that we limit the block size at all, or that the target be home computers and internet connections -- but I think there are plausible concerns about centralization risk, and I think starting small and scaling up as technology advances is a reasonable compromise.