Path: utzoo!attcan!uunet!husc6!mailrus!ames!killer!elg
From: elg@killer.DALLAS.TX.US (Eric Green)
Newsgroups: comp.arch
Subject: Re: Dhrystone 2.n Results (1 of 2)
Message-ID: <6530@killer.DALLAS.TX.US>
Date: 23 Dec 88 05:21:00 GMT
References: <357@ispi.UUCP>
Organization: The Unix(R) Connection, Dallas, Texas
Lines: 32

in article <357@ispi.UUCP>, jbayer@ispi.UUCP (Jonathan Bayer) says:
> In article <46500040@uxe.cso.uiuc.edu>, mcdonald@uxe.cso.uiuc.edu writes:
>> I still think plain text posting would be better.
> 
> Plain text would  use between 2 and 3 times as much bandwidth as compressed.
> Most systems have compress/uncompress and uuencode/uudecode available now.
> It is not reasonable to ask that everyone pay for plain text
> transmission when only a few people need it.

Note that transmitting plain text is CHEAPER than using
compress/uuencode. All major USENET sites batch and compress postings
going through them. Text is compressed, on the average, around 50%.
The result takes all common substrings and replaces them with tokens,
a process that statistically results in a file containing few common
substrings. Then UUencoding it expands the size by 1/3rd. When the
site goes to xfer a UUencoded file, the compression algorithm cannot
find many common substrings to substitute (I average about 10%
compression on UUencoded files). Huffman could probably do better on
uuencoded files, but Lempel-Zev is what we've got, since it works
better and faster on text.  Anyhow, a rough guestimate is that there's
about a 15% overhead if you compress the file then uuencode it, as vs.
sending it via plain text with compression by the transmission agent.

The keeper of the Dhrystones gave his reasons for his decision, among
which was the impossibility of sending 160-character lines via many
mailers. But efficiency is NOT one of the reasons.

--
Eric Lee Green    ..!{ames,decwrl,mit-eddie,osu-cis}!killer!elg
          Snail Mail P.O. Box 92191 Lafayette, LA 70509              
Netter A: In Hell they run VMS.
Netter B: No.  In Hell, they run MS-DOS.  And you only get 256k.