I had a folder full of random files to compress (things that wound up on my Desktop over a period of time). I’d just installed p7zip via fink (“fink install p7zip”) so I thought I’d compare it against some of the other options. The results:
| Compression | size (bytes) |
| .tar.7z | 260617470 |
| StuffIt 10 | 265169876 |
| .zip | 268555657 |
| None | 271287287 |
So it looks like tarring and then p7zipping is out ahead. The downsides of course being
- p7zip isn’t currently available via a tar commandline argument (you have to pipe, unlike bzip2 and gz which are the ‘j’ and ‘z’ tar arguments respectively).
- No Spotlight plugins for the p7zip format that I know of.