This is a comparison between compression methods (mainly 7zip and unix tools).
This is not an analysis about the different compression methods or how they compare in their algorithm against each other.
This is a simple comparison of the compression size of a small set of data.
LZMA2 is worse if you use multiple threads. It is recommended to use 1 or max. 2 threads for compression, because if you have more than 2 it splits the whole archive in 2 and makes the compression of similar content 2 times instead of once. (This information can be found in the 7zip documentation)
This test was conducted with 35 images that are part of a cosplay shooting from Megumi Koneko. A sample picture can be seen here.
Warning: These tests have been done with jpg images. The results for png images could be different.
All compressions have been done with the "Compression Level" set to "Ultra". (And as mentioned above with only 1 Thread)
The size of these 35 images without any compression: 267198693 (du -sb) / in a readable size: 255MB (du -sh)
| Size(bytes) | Program | Method | Level | DictionarySize | WordSize | SolidBlockSize |
|---|---|---|---|---|---|---|
| 261157265 | 7zip | PPMd | Ultra | 192mb | 32 | solid |
| 262354320 | 7zip | bzip2 | Ultra | 900kb | X | 128m |
| 263087428 | 7zip | lzma2 | Ultra | 64mb | 64 | solid |
| 264065788 | 7zip | lzma | Ultra | 64mb | 64 | solid |
| 264535465 | Debian10 zip | Deflation | Normal | X | X | X |
This test was conducted with 4677 text files in 1670 folders. The size of the files were 24.8MB (Size on disk was 34.2MB).
All 7zip compressions have been done with the "Compression Level" set to "Ultra". (And as mentioned above with only 1 Thread)
| Size(bytes) | Size(MB) | Program | Method | Level | DictionarySize | WordSize | SolidBlockSize |
|---|---|---|---|---|---|---|---|
| 2677842 | 2.6M | 7zip | PPMd | Ultra | 192mb | 32 | solid |
| 2749614 | 2.7M | 7zip | PPMd | Ultra | 64mb | 32 | solid |
| 2834220 | 2.8M | 7zip | lzma2 | Ultra | 1024mb | 256 | solid |
| 2843328 | 2.8M | 7zip | lzma2 | Ultra | 1024mb | 128 | solid |
| 2860599 | 2.8M | 7zip | lzma | Ultra | 64mb | 64 | solid |
| 2861099 | 2.8M | 7zip | lzma2 | Ultra | 1024mb | 64 | solid |
| 2861099 | 2.8M | 7zip | lzma2 | Ultra | 64mb | 64 | solid |
| 2934539 | 2.8M | 7zip | lzma2 | Ultra | 192mb | 32 | solid |
| 3406129 | 3.3M | tar(debian) | bzip2 | Ultra | X | X | X |
| 3409919 | 3.3M | 7zip | bzip2 | Ultra | 900kb | X | solid |
| 4247956 | 4.1M | tar(debian) | gzip | Ultra | X | X | X |
| 8482893 | 8.1M | zip(7zip) | deflate | Ultra | 32kb | 128 | X |
| 8487933 | 8.1M | zip(7zip) | deflate | Ultra | 32kb | 32 | X |
| 8581195 | 8.2M | zip(7zip) | deflate | Normal | 192mb | 32 | X |
| 8766921 | 8.4M | zip(debian) | deflate | Ultra(9) | X | X | X |
| 8786534 | 8.4M | zip(debian) | deflate | Normal(6) | X | X | X |