I had been using only this programm as a file archiver. I think that 7-zip is the best of all archivers. Work with all archive formats. Most importantly, this program is open source software. Can quickly compress many files. Speed archiving directly depends on the power of your PC. Can use all threads of CPU. Works fine with formats such as: 7z, tar, bzyp, tar.gz, zip, rar.
One of the best archive-program in the world! Just everyone should try to use this program.
Good archiver. It's free, and this is important. Also, 7-zip is embedded in the file manager, such as Total Commander.