From: Anthony Towns <aj@erisian•com.au>
To: Gavin Andresen <gavinandresen@gmail•com>,
bitcoin-dev@lists•linuxfoundation.org
Subject: Re: [bitcoin-dev] Block size following technological growth
Date: Mon, 3 Aug 2015 08:35:45 +1000 [thread overview]
Message-ID: <20150802223545.GA14286@navy> (raw)
In-Reply-To: <CABsx9T1NqBX9Tr8vRCtCeri76e0wrtkvRhEPyG9Advv_3Uqxng@mail.gmail.com>
On Thu, Jul 30, 2015 at 12:20:30PM -0400, Gavin Andresen wrote:
> On Thu, Jul 30, 2015 at 10:25 AM, Pieter Wuille via bitcoin-dev
> > Some things are not included yet, such as a testnet whose size runs ahead
> > of the main chain, and the inclusion of Gavin's more accurate sigop
> > checking after the hard fork.
> First, THANK YOU for making a concrete proposal!
> So we'd get to 2MB blocks in the year 2021. I think that is much too
> conservative, and the most likely effect of being that conservative is that
> the main blockchain becomes a settlement network, affordable only for
> large-value transactions.
I haven't seen anyone do the (trivial) maths on this. Have I just
missed it? By my count:
- blocks in 25 btc in rewards and about 0.5 btc in fees per block
- at ~$300 USD per btc, that's ~$7,650 per block
- current hashrate is ~400 PH/s; so ~240,000 PH/block works out
to having to spend about 30PH per dollar earnt.
- for comparison,
https://products.butterflylabs.com/cloud-mining-contracts.html
quotes $1.99 per GH/s for 12 months, which by my count is
60*60*24*365 / 1.99 GH/$ = 15.8 PH per dollar spent
- hashrate growth has slowed from about x4/quarter to x2/year:
sep '13: ~1PH/s
dec '13: ~4PH/s
mar '14: ~20PH/s
jun '14: ~80PH/s
sep '14: ~200PH/s
aug '15: ~400PH/s
- so, as far as I understand it, miners don't make absurd profits compared
to capital investment and running costs
- presumably, then, miners will stop mining bitcoin if the revenue/block
drops significantly at some point
- less miners means a lower hashrate; a lower hashrate makes
50% attacks easier, and that's a bad thing (especially if there's lots
of pre-loved ASIC mining hardware available cheap on ebay or alibaba)
- in about a year, the block reward halves, cutting out 12.5 btc or
~$3750 USD per block. without an increase in fees per block, miners
will just get ~$3900 USD per block
- the last time the reward for mining a block was under $4000 per block
was around oct '13, with a hashrate of ~2PH/s
- 13 btc in fees per block compared to .5 btc in fees per block is a
25x increase; which could be either an increase in fee/txn or
txns/block
- with ~500 bytes/transaction, that's ~2000 transactions per MB
- 13 btc in fees ($3900) per block means per transaction fees of
about
$2 for 1MB blocks
$1 for 2MB blocks
25c for 8MB blocks
10c for 20MB blocks
(assuming full blocks, 500 byte txns)
- comparing that to credit card or paypal fees at ~2.5% that's:
$2 -> minimum transaction $80
$1 -> minimum transaction $40
25c -> minimum transaction $10
10c -> minimum transaction $4
- those numbers only depend on the USD/BTC exchange rate in so far as
the more USD for a BTC, the more likely the block reward will pay
for hashrate without transaction fees, even with the reward reduced
to 12.5 btc/block. otherwise it's just USD/txn paying for USD/hashrate
- the reference implementation fee of 0.1mBTC/kB equates to about
3c per transaction (since it rounds up). Even 10c/transaction is more
than a 3x increase on that.
What the above says to me is that even assuming everyone starts paying
fees, the lightning network works great, and so do sidechains and whatever
else, you /still/ want to up the volume of bitcoin txns by something like
an order of magnitude above what's currently allowed within a year or so.
Cheers,
aj
next prev parent reply other threads:[~2015-08-02 22:35 UTC|newest]
Thread overview: 111+ messages / expand[flat|nested] mbox.gz Atom feed top
2015-07-30 14:25 Pieter Wuille
2015-07-30 15:04 ` Greg Sanders
2015-07-30 15:12 ` Jorge Timón
2015-07-30 16:23 ` Jameson Lopp
2015-07-30 16:36 ` Bryan Bishop
2015-07-30 16:43 ` Jameson Lopp
2015-07-30 16:36 ` Venzen Khaosan
2015-07-30 17:51 ` Jorge Timón
2015-07-30 18:00 ` Jorge Timón
2015-07-30 16:56 ` Gary Mulder
2015-07-30 17:13 ` Mark Friedenbach
2015-07-30 16:20 ` Gavin Andresen
2015-07-30 16:41 ` Suhas Daftuar
2015-07-30 16:48 ` Adam Back
2015-07-30 16:49 ` Pieter Wuille
2015-07-31 10:16 ` Mike Hearn
2015-07-31 11:43 ` Venzen Khaosan
2015-07-31 11:51 ` Jorge Timón
2015-07-31 12:15 ` Mike Hearn
2015-07-31 13:07 ` Marcel Jamin
2015-07-31 14:33 ` Jorge Timón
2015-07-31 14:58 ` Mike Hearn
2015-07-31 15:28 ` Venzen Khaosan
2015-07-31 20:09 ` Elliot Olds
2015-08-04 10:35 ` Jorge Timón
2015-08-04 11:04 ` Hector Chu
2015-08-04 11:27 ` Pieter Wuille
2015-08-04 11:34 ` Hector Chu
2015-08-04 12:10 ` Venzen Khaosan
2015-08-04 13:13 ` Jorge Timón
2015-08-04 13:28 ` Hector Chu
2015-08-04 13:42 ` Venzen Khaosan
2015-08-04 17:59 ` Jorge Timón
2015-08-04 13:12 ` Gavin Andresen
2015-08-04 13:54 ` Pieter Wuille
2015-08-04 14:30 ` Venzen Khaosan
2015-08-04 14:43 ` [bitcoin-dev] Fwd: " Venzen Khaosan
2015-08-04 14:45 ` [bitcoin-dev] " Alex Morcos
2015-08-05 8:14 ` Gareth Williams
2015-08-04 11:59 ` Jorge Timón
2015-08-04 12:19 ` Hector Chu
2015-08-04 13:34 ` Venzen Khaosan
2015-08-04 13:37 ` Jorge Timón
2015-08-05 7:29 ` Elliot Olds
2015-08-06 1:26 ` Jorge Timón
2015-08-06 13:40 ` Gavin Andresen
2015-08-06 14:06 ` Pieter Wuille
2015-08-06 14:21 ` Gavin Andresen
2015-08-06 14:53 ` Pieter Wuille
[not found] ` <CABsx9T0B2bZrFHxYR_QNwBmxskQx31zt=QE5BJAYjcOo7wbo3A@mail.gmail.com>
2015-08-06 15:24 ` [bitcoin-dev] Fwd: " Gavin Andresen
2015-08-06 15:26 ` Pieter Wuille
2015-08-06 18:43 ` Michael Naber
2015-08-06 18:52 ` Pieter Wuille
2015-08-07 16:06 ` Thomas Zander
2015-08-07 16:30 ` Pieter Wuille
2015-08-07 17:00 ` Thomas Zander
2015-08-07 17:09 ` Pieter Wuille
2015-08-07 21:35 ` Thomas Zander
2015-08-07 22:53 ` Adam Back
2015-08-08 16:54 ` Dave Scotese
2015-08-07 17:50 ` Gavin Andresen
2015-08-07 18:05 ` Jameson Lopp
2015-08-07 18:10 ` Pieter Wuille
2015-08-07 21:43 ` Thomas Zander
2015-08-07 22:00 ` Thomas Zander
2015-08-06 16:19 ` [bitcoin-dev] " Tom Harding
2015-08-06 21:56 ` Peter Todd
2015-08-06 15:25 ` Jorge Timón
2015-08-06 16:03 ` Gavin Andresen
2015-08-06 16:11 ` Mike Hearn
2015-08-06 17:15 ` Jorge Timón
2015-08-06 19:42 ` Gavin Andresen
2015-08-06 20:01 ` Pieter Wuille
2015-08-06 21:51 ` Jorge Timón
2015-08-06 23:09 ` Elliot Olds
2015-08-10 19:28 ` Jorge Timón
2015-08-11 5:48 ` Elliot Olds
2015-08-09 18:46 ` [bitcoin-dev] What Lightning Is Tom Harding
2015-08-09 18:54 ` Mark Friedenbach
2015-08-09 20:14 ` Hector Chu
[not found] ` <CAOG=w-s9KsaPwveSpgdvsVTWUDV77YY7Em7NZGyxSQMMCccYSg@mail.gmail.com>
2015-08-09 20:48 ` Hector Chu
2015-08-10 4:48 ` Joseph Poon
2015-08-10 17:03 ` odinn
2015-08-10 17:14 ` Pieter Wuille
2015-08-10 17:45 ` odinn
2015-08-09 21:27 ` Tom Harding
2015-08-09 21:40 ` Chris Pacia
2015-08-09 21:45 ` Hector Chu
2015-08-09 21:57 ` Patrick Strateman
2015-08-09 22:03 ` Hector Chu
2015-08-09 22:36 ` Patrick Strateman
2015-08-10 1:52 ` Tom Harding
2015-08-10 3:31 ` Patrick Strateman
2015-08-09 22:06 ` Patrick Strateman
2015-08-09 22:09 ` Hector Chu
2015-08-09 22:27 ` Patrick Strateman
2015-08-09 22:30 ` Hector Chu
2015-08-09 22:44 ` Gavin Andresen
2015-08-09 22:51 ` Btc Drak
2015-08-10 8:27 ` Thomas Zander
2015-08-10 8:36 ` Patrick Strateman
2015-08-10 4:39 ` Joseph Poon
2015-08-10 21:02 ` Anthony Towns
2015-08-10 21:19 ` Anthony Towns
2015-08-10 21:43 ` Adam Back
2015-08-11 9:01 ` Hector Chu
2015-08-11 17:17 ` Simon Liu
2015-07-31 14:52 ` [bitcoin-dev] Block size following technological growth Bryan Bishop
2015-07-30 17:46 ` Jorge Timón
2015-08-02 22:35 ` Anthony Towns [this message]
2015-07-30 20:20 ` Thomas Zander
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