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Date: Sat, 30 May 2015 09:57:32 -0400
Message-ID: <CABsx9T0kbRe31LMwk499MQUw225f5GGd67GfhXBezHmDqxkioA@mail.gmail.com>
From: Gavin Andresen <gavinandresen@gmail.com>
To: Chun Wang <1240902@gmail.com>
Content-Type: multipart/alternative; boundary=001a11c351525d6f7905174cf954
Cc: Bitcoin Dev <bitcoin-development@lists.sourceforge.net>
Subject: Re: [Bitcoin-development] Block Size Increase Requirements
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On Fri, May 29, 2015 at 7:42 PM, Chun Wang <1240902@gmail.com> wrote:

> Hello. I am from F2Pool. We are currently mining the biggest blocks on
> the network.


Thanks for giving your opinion!


> Bad miners could attack us and the network with artificial
> big blocks.


How?

I ran some simulations, and I could not find a network topology where a big
miner producing big blocks could cause a loss of profit to another miner
(big or small) producing smaller blocks:

http://gavinandresen.ninja/are-bigger-blocks-better-for-bigger-miners

(the 0.3% advantage I DID find was for the situation where EVERYBODY was
producing big blocks).


> We think
> the max block size should be increased, but must be increased
> smoothly, 2 MB first, and then after one or two years 4 MB, then 8 MB,
> and so on. Thanks.


Why 2 MB ?   You said that server bandwidth is much more expensive in
China; what would be the difference in your bandwidth costs between 2MB
blocks and 20MB blocks?


-- 
--
Gavin Andresen

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<div dir=3D"ltr"><div class=3D"gmail_extra"><div class=3D"gmail_quote">On F=
ri, May 29, 2015 at 7:42 PM, Chun Wang <span dir=3D"ltr">&lt;<a href=3D"mai=
lto:1240902@gmail.com" target=3D"_blank">1240902@gmail.com</a>&gt;</span> w=
rote:<br><blockquote class=3D"gmail_quote" style=3D"margin:0px 0px 0px 0.8e=
x;border-left-width:1px;border-left-color:rgb(204,204,204);border-left-styl=
e:solid;padding-left:1ex">Hello. I am from F2Pool. We are currently mining =
the biggest blocks on<br>
the network. </blockquote><div><br></div><div>Thanks for giving your opinio=
n!</div><div><br></div><div>=C2=A0</div><blockquote class=3D"gmail_quote" s=
tyle=3D"margin:0px 0px 0px 0.8ex;border-left-width:1px;border-left-color:rg=
b(204,204,204);border-left-style:solid;padding-left:1ex">Bad miners could a=
ttack us and the network with artificial<br>
big blocks.</blockquote><div><br></div><div>How?</div><div><br></div><div>I=
 ran some simulations, and I could not find a network topology where a big =
miner producing big blocks could cause a loss of profit to another miner (b=
ig or small) producing smaller blocks:</div><div><br></div><div><a href=3D"=
http://gavinandresen.ninja/are-bigger-blocks-better-for-bigger-miners">http=
://gavinandresen.ninja/are-bigger-blocks-better-for-bigger-miners</a><br></=
div><div><br></div><div>(the 0.3% advantage I DID find was for the situatio=
n where EVERYBODY was producing big blocks).</div><div>=C2=A0</div><blockqu=
ote class=3D"gmail_quote" style=3D"margin:0px 0px 0px 0.8ex;border-left-wid=
th:1px;border-left-color:rgb(204,204,204);border-left-style:solid;padding-l=
eft:1ex">We think<br>
the max block size should be increased, but must be increased<br>
smoothly, 2 MB first, and then after one or two years 4 MB, then 8 MB,<br>
and so on. Thanks.</blockquote><div><br></div><div>Why 2 MB ? =C2=A0 You sa=
id that server bandwidth is much more expensive in China; what would be the=
 difference in your bandwidth costs between 2MB blocks and 20MB blocks?</di=
v><div><br></div><div>=C2=A0</div></div>-- <br><div class=3D"gmail_signatur=
e">--<br>Gavin Andresen<br></div>
</div></div>

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