Zip, Rar, 7z, Gzip, BZip2, Tar etc. I'm hearing 7z is the flavor of the month, why? Is it best for all situations or are there better choices for specific situations.
Or maybe the actual file archiver ie WinZip, WinRar, 7Zip etc (as opposed the format) has a bigger effect?
In your answer could you describe what sort of speed/compression tradeoff your mentioned format uses.
Please provide links to any empirical tests that back up your answer.
Background: I need to backup a custom search index that creates about 3000 relatively small files (less then 10MB), each containing a lot of repetitive data.
(As usual Wikipedia has a relevant article but the section on performance comparison is brief.)