Expansion Ratings

At least a few people out there want to decompress files for some strange reason and might be interested in how fast the various compression programs do this. Myself, I always go fix a snack, watch some Star Trek, read a book, or carry on intellectual conversations while my Mac decompresses files. I guarantee that me method will give you the best results (i.e. you'll enjoy yourself instead of sitting around watching progress bars). But, since I've so often been reminded that I'm probably not a good indication of the real world, here we go...

I did two decompression tests for each of five programs: Compact Pro 1.30, DiskDoubler 3.1, StuffIt 1.5.1, StuffIt Classic 1.6, and StuffIt Deluxe 2.0. All tests, as before, were performed on a Mac SE/30, System 6.0.7 running under Finder, and using the Desktop Manager. The first test was to decompress a StuffIt 1.5.1 archive containing all the previously compressed files: Binaries, Graphics, and Text Files. The second test was to decompress one file containing the same files in the application's native format. Compact Pro has only one format (simple, eh?). For DiskDoubler, this was a "combined" file compressed with Method A. For StuffIt 1.5.1, this was a file compressed with "Try both." For StuffIt Classic and Deluxe, this was a file compressed with "Best Guess." I decided to use these formats because I thought they would be the most commonly used in each case (I could be wrong) and since decompression times will vary widely depending on %-saved, original data type, etc. (So use these numbers only as a rough guideline!)

Two figures are given for each application. For the first test, we have total time to decompress the 2,527,112 byte file (the faster, the better) and a speed relative to StuffIt 1.5.1 (the larger the number, the better). For the second test, we have total time to decompress the file and a kilobytes/minute decompression speed (again, the larger the better).

Time to decompress a StuffIt 1.5.1 archive:

                     Time       Normalized
  Compact Pro        2:41         1.95
  DiskDoubler        3:51         1.36
  StuffIt Classic    5:07         1.02
  StuffIt 1.5.1      5:14         1.00
  StuffIt Deluxe     5:24         0.97

Time to decompress a native format file:

                     Time        K/min
  Compact Pro        3:26         732
  DiskDoubler        2:23         635
  StuffIt 1.5.1      5:14         472
  StuffIt Classic    7:11         390
  StuffIt Deluxe     7:33         365

Question: "So, which one should I use?"

Answer: "It depends on what you want. Read on."