Subject: Re: [bitcoin-dev] Draft BIP : fixed-schedule block size increase

From: Gavin Andresen <[email-masked]>
Date: Tue, 23 Jun 2015 16:12:17 -0400

On Tue, Jun 23, 2015 at 3:28 PM, Peter Todd <[email-masked]> wrote:

> On Mon, Jun 22, 2015 at 02:18:19PM -0400, Gavin Andresen wrote:
> > ==Rationale==
> >
> > The initial size of 8,000,000 bytes was chosen after testing the current
> > reference implementation code with larger block sizes and receiving
> > feedback from miners stuck behind bandwidth-constrained networks (in
> > particular, Chinese miners behind the Great Firewall of China).
> >
> > The doubling interval was chosen based on long-term growth trends for CPU
> > power, storage, and Internet bandwidth. The 20-year limit was chosen
> > because exponential growth cannot continue forever.
>
> Wladimir noted that 'The original presented intention of block size
> increase was a one-time "scaling" to grant time for more decentralizing
> solutions to develop'
>
> Comments?
>

Consensus is that this process is too painful to go through once a year.  I
agree.

If you disagree and would like to see a Blocksize Council meet once a year
to issue a decree on what the maximum block size shall be for the next
year, then propose a process for who gets to sit on the Council and how
their decrees are enforced.....

>
> In particular, if bandwidth scaling doesn't go according to your plan,
> e.g. the exponential exponent is too large, perhaps due to technological
> growth not keeping pace, or the political realities of actual bandwidth
> deployment making theoretical technological growth irrelevant, what
> mechanism will prevent centralization? (if any)

Simulations show that:

Latency/bandwidth matter for miners.  Low latency, high bandwidth is
better. However, miners with bad connectivity can simply create smaller
blocks...

... until transaction fees become significant.  But by the time that
happens, protocol optimizations of block propagation will make the block
size an insignificant term in the "how profitable is it to mine in THIS
particular place on the Internet / part of the world" equation.

(Reference:
https://www.mail-archive.com/[email-masked]/msg08224.html
)

So: for the immediate future, there is no problem. And in the long term,
there is no problem.

-- 
--
Gavin Andresen