I needed to e-mail a 62 MB MOSS log file to MS support. Yeah, there were in fact some problems in our MOSS installation?!
Knowing that RAR (which I prefer for the reasons you will soon find out) wasn't necessarily available for MS support personnel and that you can't open packages made with newer WinRAR with older versions of WinRAR, I was polite enough to ZIP the log file. A relatively good compression ratio of 13%, so the file was about 8,5 MB, not bad.
Well, of course our Exchange server bounced the mail back complaining about the size of the email (which was near but under 10 MB, so I don't even dare to guess how low the limit on the server really is).
Well, I first opened a new e-mail message window and started writing a complaint to our IT Support so that they'd increase the e-mail size limit, but being a nerd I decided to try compressing the file with RAR as I've had good experiences using it.
Guess what, with RAR, the compression ratio was 0% and file size 561 KB! I've been impressed several times with RAR's compression ratio, but I believe this one is something I have to tell my grandchildren (one day) about.
I don't think WinRAR uses the latest version of ZIP, so this comparison is not probably a fair, but as I only want to use one software for my compression needs, it is fair comparison for me.
These screen shots show the files when Best compression ratio was used in both RAR and ZIP.
ZIP, 8,6 MB:
RAR, 0,56 MB