Return-Path: Received: from smtp1.linuxfoundation.org (smtp1.linux-foundation.org [172.17.192.35]) by mail.linuxfoundation.org (Postfix) with ESMTPS id DFD3C7D for ; Tue, 4 Aug 2015 14:22:21 +0000 (UTC) X-Greylist: whitelisted by SQLgrey-1.7.6 Received: from mail-wi0-f174.google.com (mail-wi0-f174.google.com [209.85.212.174]) by smtp1.linuxfoundation.org (Postfix) with ESMTPS id E0B2B1C5 for ; Tue, 4 Aug 2015 14:22:20 +0000 (UTC) Received: by wibud3 with SMTP id ud3so179548903wib.1 for ; Tue, 04 Aug 2015 07:22:19 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20120113; h=mime-version:sender:in-reply-to:references:date:message-id:subject :from:to:cc:content-type; bh=hrfvIWCs2SvV2B/fKIRKc+TfDLpJCJGTWfHJBQOeTjA=; b=kbB1xKetM2i/tkVGzOngaLN6JjKU9m5HdFuqZ7D4kwSzEHUEMQtfrLQWfW+GudqwKF OT4BBELZ4yCJb/wzOO//eNrKdYpOIc2Wl1Vkdm27h2V8nfRiNUhFFR2MubOWxdITS5oz 1BO94vaAUWT1ByNIsybloxnTt+bO/UYjS7RQulfBdGD1WRKST/PpCh0vnxYXtq5jOXmj rPpolrJZ3rhOyuG1B12G7/pVfwIiPQ2bMYAa8w5eEf8IZlmNkdwCWDW0vzX3aeTIRnFC Ly5tEU5iZuRZJq2JXInGsOPBuuaKtVlSlyZz/exb7MJWgHcdofd0oVwnv+ozUm8x5CQ9 M1HA== MIME-Version: 1.0 X-Received: by 10.180.96.1 with SMTP id do1mr7963315wib.37.1438698139680; Tue, 04 Aug 2015 07:22:19 -0700 (PDT) Sender: anthony.j.towns@gmail.com Received: by 10.28.143.141 with HTTP; Tue, 4 Aug 2015 07:22:19 -0700 (PDT) In-Reply-To: References: Date: Wed, 5 Aug 2015 00:22:19 +1000 X-Google-Sender-Auth: CXVMCeBkxW26GJYTc7eiWFHLyP4 Message-ID: From: Anthony Towns To: Gavin Andresen Content-Type: multipart/alternative; boundary=f46d04447fc58e0a37051c7d0385 X-Spam-Status: No, score=-2.6 required=5.0 tests=BAYES_00,DKIM_SIGNED, DKIM_VALID,FREEMAIL_FROM,HTML_MESSAGE,RCVD_IN_DNSWL_LOW autolearn=ham version=3.3.1 X-Spam-Checker-Version: SpamAssassin 3.3.1 (2010-03-16) on smtp1.linux-foundation.org Cc: Bitcoin Dev Subject: Re: [bitcoin-dev] Eli Dourado on "governance" X-BeenThere: bitcoin-dev@lists.linuxfoundation.org X-Mailman-Version: 2.1.12 Precedence: list List-Id: Bitcoin Development Discussion List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Tue, 04 Aug 2015 14:22:22 -0000 --f46d04447fc58e0a37051c7d0385 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: quoted-printable On 4 August 2015 at 01:22, Gavin Andresen via bitcoin-dev < bitcoin-dev@lists.linuxfoundation.org> wrote: > And the preliminary results of using a prediction market to try to wrestl= e > with the tough tradeoffs looks roughly correct to me, too: > https://blocksizedebate.com/ > =E2=80=8BThe scicast prediction market is shutdown atm (since early July?) = so those numbers aren't live. But... Network hash rate 3,255.17 PH/s (same block size) 5,032.64 PH/s (block size increase) 4,969.68 PH/s (no replace-by-fee) 3,132.09 PH/s (replace-by-fee) Those numbers seem completely implausible: that's ~2.9-3.6 doublings of the current hashrate (< 400PH/s) in 17 months, when it's taken 12 months for the last doubling, and there's a block reward reduction due in that period too. (That might've been a reasonable prediction sometime in the past year, when doublings were slowing from once every ~45 days to once a year; it just doesn't seem a supportable prediction now) That the PH/s rate is higher with bigger blocks is surprising, but given that site also predicts USD/BTC will be $280 with no change but $555 with bigger blocks, so I assume that difference is mostly due to price. Also, 12.5btc at $555 each is about 23 btc at $300 each, so if that price increase is realistic, it would compensate for almost all of the block reward reduction. Daily transaction volume 168,438.22 tx/day (same block size) 193,773.08 tx/day (block size increase) 192,603.80 tx/day (no replace-by-fee) 168,406.73 tx/day (replace-by-fee) That's only a 15% increase in transaction volume due to the block size increase; I would have expected more? 168k-194k tx/day is also only a 30%-50% increase in transaction volume from 130k tx/day currently. If that's really the case, then a 1.5MB-2MB max block size would probably be enough for the next two years... (Predicting that the node count will drop from ~5000 to ~1200 due to increasing block sizes seems quite an indictment as far as centralisation risks go; but given I'm not that convinced by the other predictions, I'm not sure I want to give that much weight to that one either) Cheers, aj --=20 Anthony Towns --f46d04447fc58e0a37051c7d0385 Content-Type: text/html; charset=UTF-8 Content-Transfer-Encoding: quoted-printable
On 4 August 2015 at 01:22, = Gavin Andresen via bitcoin-dev <bitcoin-dev@lists.linuxfoundation.org> wrote:
And the preliminary results of using a predictio= n market to try to wrestle with the tough tradeoffs looks roughly correct t= o me, too:
=

=E2=80=8BThe scicast prediction market is shutdown atm (since early J= uly?) so those numbers aren't live. But...

Network hash rate
<= div class=3D"gmail_default"> 3,255.17 PH/s =C2=A0(same block size)
5,032.64 PH/s =C2= =A0(block size increase)

4,969= .68 PH/s =C2=A0(no replace-by-fee)
3,132.09 PH/s =C2=A0(replace-by-fee)

Those numbers seem completely i= mplausible: that's ~2.9-3.6 doublings of the current hashrate (< 400= PH/s) in 17 months, when it's taken 12 months for the last doubling, an= d there's a block reward reduction due in that period too. (That might&= #39;ve been a reasonable prediction sometime in the past year, when doublin= gs were slowing from once every ~45 days to once a year; it just doesn'= t seem a supportable prediction now)

<= font face=3D"monospace">That the PH/s rate is higher with bigger blocks is = surprising, but given that site also predicts USD/BTC will be $280 with no = change but $555 with bigger blocks, so I assume that difference is mostly d= ue to price. Also, 12.5btc at $555 each is about 23 btc at $300 each, so if= that price increase is realistic, it would compensate for almost all of th= e block reward reduction.

Daily= transaction volume
168,438.22 tx/day =C2=A0(same block size)
193,773.08 tx/day =C2=A0(block size increase)

=
192,603.80 tx/day =C2=A0(no replace-by-fee)
168,406.73 = tx/day =C2=A0(replace-by-fee)
=
That's only a 15% increase in transaction volume due to the bl= ock size increase; I would have expected more? 168k-194k tx/day is also onl= y a 30%-50% increase in transaction volume from 130k tx/day currently. If t= hat's really the case, then a 1.5MB-2MB max block size would probably b= e enough for the next two years...

(Predic= ting that the node count will drop from ~5000 to ~1200 due to increasing bl= ock sizes seems quite an indictment as far as centralisation risks go; but = given I'm not that convinced by the other predictions, I'm not sure= I want to give that much weight to that one either)

Cheers,
aj

--
Anthony Towns <aj@erisian.com.au>
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