Strange Compression Comparisons

Well, if you're desparate to do bzip2 under windows, or pretty much any other cool GNU thing (find, grep, less, wget, etc) you can download them at http://gnuwin32.sourceforge.net/packages.html

C:\Documents and Settings\me>bzip2 --version bzip2, a block-sorting file compressor. Version 1.0.1, 23-June-2000.

  • adm
    Aaron D. Marasco wrote:
    
    > OK, a quick test. I just got a PowerPoint presentation. I am not going to mess with dictionary sizes or anything, leaving those default.
    >
    > PPT: 1,440,768 bytes (Original file)
    > ZIP: 1,311,093 (Dunno what did it, I received it this way)
    > RAR: 1,303,276 (RAR 3.20 beta 4, which does the 'new' RAR compression, default setting)
    > RAR: 1,303,241 (Same version, told it MAX compress "m5" command line)
    > ACE: 1,305,286 (2.0 compression, normal)
    > ACE: 1,309,770 (1.0 compression, normal)
    > ACE: 1,305,274 (2.0 compression, max)
    > GZ: 1,311,109 (Created by WinACE 2.5 max compression)
    > LZH: 1,440,901 (Created by WinACE 2.5 max compression) (-- this is BIGGER. This surprises me and tells me that PPT may already be compressed?
    > .TAR.GZ: 1,311,614 (Created by WinACE 2.5 max compression)
    > CAB: 1,304,092 (Created by WinACE 2.5 max compression)
    > ZIP: 1,310,299 (Created by WinACE 2.5 max compression)
    > JAR: 1,310,299 (Created by WinACE 2.5 max compression -- I think .JAR are just renamed .ZIP anyway)
    > BZ2: 1,337,976 (bzip2 Version 1.0.2 - I couldn't see a command line to change compression)
    > GZ: 1,310,209 (gzip -9 gzip 1.3 [1999-12-21]) (-- I've never seen GZIP be smaller than BZ2?!?!?
    >
    > And now sorted:
    > [[email protected] shared]# sort -t' ' +1 tempo
    > RAR: 1,303,241 (Same version, told it MAX compress "m5" command line)
    > RAR: 1,303,276 (RAR 3.20 beta 4, which does the 'new' RAR compression, default setting)
    > CAB: 1,304,092 (Created by WinACE 2.5 max compression)
    > ACE: 1,305,274 (2.0 compression, max)
    > ACE: 1,305,286 (2.0 compression, normal)
    > ACE: 1,309,770 (1.0 compression, normal)
    > GZ: 1,310,209 (gzip -9 gzip 1.3 [1999-12-21]) (-- I've never seen GZIP be smaller than BZ2?!?!?
    > ZIP: 1,310,299 (Created by WinACE 2.5 max compression)
    > JAR: 1,310,299 (Created by WinACE 2.5 max compression -- I think .JAR are just renamed .ZIP anyway)
    > ZIP: 1,311,093 (Dunno what did it, I received it this way)
    > GZ: 1,311,109 (Created by WinACE 2.5 max compression)
    > .TAR.GZ: 1,311,614 (Created by WinACE 2.5 max compression)
    > BZ2: 1,337,976 (bzip2 Version 1.0.2 - I couldn't see a command line to change compression)
    > PPT: 1,440,768 bytes (Original file)
    > LZH: 1,440,901 (Created by WinACE 2.5 max compression) (-- this is BIGGER. This surprises me and tells me that PPT may already be compressed?
    

I think these are slightly skewed, but RAR just edged out ACE. Again, I think this is a recompression on compressed data. I would doubt that MS-CAB would normally beat ACE. This is not a directory of plaintext. You can even see that ACE can make GZip compat archives, but it was slightly larger than GZip itself. And ACE also made a smaller ZIP file than what I assume was WinZip.

And since I already bought WinACE, it's good enough.

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