Compression ratio results are very dependent upon the data used for the tests. We compared 7-Zip with some of the leading commercial archivers: PKZIP 2.04g, WinZip 7.0.
FILE SET: The Canterbury Corpus (11 files totaling 2,810,784 bytes, popular file set used to compression rates).
| Archiver | Compressed size | Ratio |
|---|---|---|
| 7-Zip (zip format) | 676284 | 100% |
| PKZIP 2.04g -ex | 726047 | 107% |
| WinZip 7.0 (Max) | 731499 | 108% |
7z is the new archive format, providing a high compression ratio.
FILE SET: The GIMP 1.2.4 for Windows after full installation (127 subfolders, 1304 files totaling 27,128,826 bytes). The GIMP is the GNU Image Manipulation Program. It can be downloaded from www.gimp.org.
| Archiver | Compressed size | Ratio |
|---|---|---|
| 7-Zip (7z format) | 5445402 | 100% |
| WinRAR 3.10 | 6004155 | 110% |
| WinAce 2.3 | 6242424 | 115% |
| CABARC 1.0 | 6455327 | 119% |
| 7-Zip (zip format) | 9461621 | 174% |
| PKZIP 2.50 | 9842800 | 181% |
7-Zip provides the best compression ratio for GZIP format. The compression ratio is equal to its compression ratio for ZIP format (above).
7-Zip provides superior decompression speed for RAR archives.
For solid archives it decompresses only the minimum number of files
needed. For example,
consider a solid archive archive.rar containing 100000 files
created by the command:
rar a archive.rar -s100 * -r
In this solid archive, each group of 100 files is compressed as one big file.
To extract one file from that archive,
7-Zip will decompress (in memory) only some files from one group.
As a result, 7-Zip can provide the combined advantages
of solid compression and high speed of decompression.