WinRAR compresses by default each file separately. With 30 versions of the site, method 1 weights 6Gb, while a 7zip WIM file inside a 7zip LZMA2 file weights only 2Gb! New edit: My backups were growing and now have many images files.
I would give this 2 steps method a try using your specific set of files and compare it against method 1. Sadly is not the same backup file I used in the test years ago, but I could compress the WIM file at 70% of it size.
Update edit: Thanks to suggestion in comments, I tried to use 7zip LZMA2 compression (dictionary size seems to have no difference) over the 7zip WIM file. While standard 7zip or WinRar compression gave me a file of about 400/500Mb, these options gave me a file of (1) 80Mb, (2) 100Mb & (3) 170Mb respectively. sql, etc.) with a total size of 1Gb (100Mb average per folder). I had 10 folders with different versions of a web site (with files such as.
The maximum value for dictionary size is 1536 MB, but 32-bit version of 7-Zip allows to specify up to 128 MB dictionary. You must specify the size in bytes, kilobytes, or megabytes. Usually, a big number gives a little bit better compression ratio and slower compression process. The default value is 32 for normal mode and 64 for maximum and ultra modes. mfb=273 - Sets number of fast bytes for LZMA.
t7z - Set type of archive (7z in your case) Here is the options: 7za a -r -t7z -m0=lzma2 -mx=9 -mfb=273 -md=29 -ms=8g -mmt=off -mmtf=off -mqs=on -bt -bb3 archife_file_name.7z /path/to/files