Path: utzoo!attcan!utgpu!jarvis.csri.toronto.edu!mailrus!wuarchive!udel!mmdf
From: ALBRECHT@caliph (Steve Albrecht)
Newsgroups: comp.sys.amiga
Subject: Re: zip vs. other archivers
Message-ID: <1669@nigel.udel.EDU>
Date: 14 Oct 89 14:01:42 GMT
Sender: mmdf@udel.EDU
Lines: 44

I recently benchmarked LHARC vrs ZIP, ZOO, and ARC.  Although I did this
on an IBM PC/AT, the results shoud apply equally to Amiga provided that
the algorithms are bug-free, or similarly buggy :-) .

I used PC versions: LHARC 1.13C, PKZIP 1.01, PKARC 3.61, PKARC 3.5, ARC 6.02,
ARC 5.32, and ZOO 2.01.

There was no significant difference between the 4 versions of ARC, compression-
wise.

LHARC was the best(53% compression power on my sample of real, randomly selectedshareware/freeware submission).

PKZIP was a close second with a cp of 50% (resulting files were 5% larger than
those produced by LHARC).

All ARC version and ZOO were clustered at cp=38-40, with files 20% larger than
those produced by LHARC.

I also comapred features and speed of pack and unpack.  Since those may differ
significantly from PC to Amiga, I won't bother to report them here.

Note: compression power(cp) is    (unpacked size)  -  (packed size)
                                  ---------------------------------
                                           (unpacked size)

      a worthless compression algorithm would acheive a cp of 0 (0%),
      while an (impossibly) ideal one would acheive a cp of 1 (100%).

Translating reults to Amiga:  Since LHARC1.13C is the ONLY version (I know of)
that was circulated for IBM PC, Amiga LHARC .50 is the same, or (doubtfully)
even later(better).  ZOO should be the same, since no new versions have appearedin some time.  ARC is ARC, though PK's implementation always seems just a
tiny bit better (compression-wise) than S.E.A's.  I don't know what version
(of who the author is) of the Amiga version of ZIP.  Since PKWARE does not
circulate its sources...


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) Steve Albrecht - IntelliCorp, Inc. - Knowledge Systems Product Development )
( "Opinions expressed here are my own, if anyone's, and not my employer's."  (
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