For those of you interested in archivers for compressing files on various
computer systems, here is the latest report that I have come across.
******************************* CLIP *******************************
I was asked to include uncompress times along with everything else
in this posting -- so this is it. Column 2 of the times is uncompress
on the 4.77 MHz 8088 machine.
Packing Test for Pak/PKArc/PKZip/Zoo/LHArc/Hyper/ARJ/ARC
--------------------------------------------------------
The files used in the test are given below, and is the entire
distribution of the terminal emulation programme, QVT 3.74. Here, A
denotes an ASCII file, B is a binary file. The first two timing columns
given are for compression and decompression on a Zenith 151 running a V20
chip/8087 at 4.77 MHz on a 20Mb fully compressed harddisk, the third is the
compress time for a 12 MHz 80286 clone on a 40Mb fully compressed harddisk.
DEFAULT VT 3159 A
QVT HLP 17386 A
QVT_BBS EXE 169929 B
QVT_KB MAP 2219 A
READ ME 12444 A
RELNOTES 374 20342 A
------
225479
Compression Tool Extension Time Taken Final Size % Compression
---------------- --------- ---------------- ---------- -------------
PKArc 3.61 ARC 0:43 0:36 7.6 146,507 35.0%
Zoo 2.01 ZOO 1:41 1:05 18.1 147,819 34.4%
Zoo 2.10 ZOO 4:03 1:26 148,250 34.3%
tar/compress (16 bit) xxx 2:00 1:29 150,157 33.4%
cpio/compress ( " ) xxx 2:26 149,927 33.5%
SEA ARC 6.02 ARC 1:54 1:09 152,916 32.2%
LArc 3.33 LZS 3:05 123,363 45.3%
PKZip 1.10 ZIP 1:44 0:30 16.6 109,335 51.5%
Pak 2.51 PAK/ARC/ZIP 2:35 0:55 25.7 109,019 51.7%
Hyper 2.50 HYP 2:57 2:24 23.6 109,771 51.3%
LHArc 2.12 LZH 3:07 0:51 26.1 104,488 53.7%
ARJ 1.10 ARJ 5:28 104,634 53.6%
Zoo 2.10 (high comp) ZOO 7:34 1:20 104,804 53.5%
ARJ 2.10 ARJ 2:41 1:01 24.0 102,692 54.5%
There are now essentially five groupings of archivers with the new,
fast release of ARJ 2.10. Best compression/time combination yet. Very
impressive, especially with a 50% improvement in compression speeds over
the previous (1.xx) release. Now, we will have to see if LHArc can catch
up on its next release, since it is seems unlikely Phil Katz will do any
more on compression. Pak and Hyper are out of it, unless a dramatic speed
improvement can be realized. I do not expect this. ARC from SEA is
essentially useless compared to the others -- the old ZOO has better
compression/times!
Current recommendations are PKZip and LHArc, in terms of compression,
speed, and usage. ARJ is better, but must become more popular in usage
before I can give it an enthusiastic recomendation. Note that LHArc and
ARJ both are capable of compressing LZEXE files even further -- PKZip is
not.
The new version of ZOO is a surprise, especially with the slow time
for the default and the high compression otherwise. The speed is a bug to
me and has to be fixed. It might be important to note that ZOO is
available across nearly all computer types -- IBM-PC, Amiga, unix, VAX/VMS.
PKZip is available on Amiga as well as PCs, unZip only on most systems.
LHARC exists on unix as well as DOS, as does ARC 5 (not 6 yet, I believe).
I have not seen ARJ outside of the DOS world.
So, when do we reach the theoretical maximum compression?
--
Original post by:
Arnold Gill --- astrophysician in training
