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Subject: Re: Namilov egtb compression: Bittorrent?

Author: Robert Hyatt

Date: 09:06:45 08/15/05

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On August 15, 2005 at 11:33:55, Joshua Shriver wrote:

>Interesting read. Thanks for the reply sir.
>
>By chance has there been any thought about setting up a BT site for the TB's? At
>least for the 6men?

not that I know of.  making downloads easier would probably get us into more hot
water with the UAB network folks.  They continually point out that we are
smoking 70+ megabits per second, 24 hours a day, 7 days a week, with the current
ftp server. :)


>
>
>
>>
>>
>>There is a big problem.  Suppose you want to read the byte displaced
>>1,000,000,000 from the beginning.  Serial compression requires serial
>>decompression, reading and decompressing all the data before the byte you want,
>>so you can recognize the byte you want.
>>
>>The EGTB compression uses "blocks" so that we can read in a single block from
>>anywhere in the file, and just have to decompress that block, rather than all
>>the preceeding data.  You can make the blocksize bigger to improve the
>>compression, but it costs you at decompression time, which is, unfortunately,
>>right in the middle of your tree search.  NPS goes into the toilet.
>>
>>When we started this stuff, I ran a _bunch_ of tests for Eugene to choose the
>>best compression blocksize from a tree-search vs compression efficiency point of
>>view...



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