Get Maximum Compression from 7zip compression algorithm

command-line compression 7zip lzma
Shilpi Agrawal picture Shilpi Agrawal · Mar 16, 2015 · Viewed 42k times · Source

I am trying to compress some of my large document files. But most of files are getting compresses by only 10% maximum. I am using 7zip Terminal Commands.

7z a filename.7z -m0=LZMA -mx=9 -mmt=on -aoa -mfb=64 filename.pptx

Any suggestion on changing parameters. I need at least 30% compression ratio.

Answer

MC ND picture MC ND · Mar 16, 2015

.pptx files or .docx files are internally .zip archives. You can not expect a lot of compression on an already compressed file.

Documentation states lzma2 handles better data that can not be compressed, so you can try with 

7z a -m0=lzma2 -mx filename.7z filename.pptx

But the required 30% is almost unreachable.

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