When some people going to compress any file via 7zip software, they ask what is dictionary size in 7zip & how does affect file compression if I select 64 MB,128 MB, 1024 MB, etc.
Actually, dictionary size you can understand easily by knowing their effect – when you select a higher dictionary size then the file will compress better, but it takes more time and RAM Usages.
Best Compression Method is LZMA in 7zip software because It provides high compression and very fast decompression. So when you select LZMA compression method + When you select dictionary size up to Maximum ( for example – 1024 MB) then any file will compress much better.
You can check here – how to highly compress the file using 7zip.
I hope you understood what is dictionary size in 7zip & how does affect file compression.