Microsoft Office save XML zipped files

[BetaTester]

Most office backups, are compounds by Microsoft Office files type, as docx and xlsx.

These files are zipped XML, a standard save similar to the OpenOffice.

For example, testing 7zip "PPMD 1024MB word32", Rar "Best", and FreeArc "-mx" in my doc.

LTT2 expand-----148.195.235 bytes
LTT2.docx----------4.322.991 bytes
LTT2.docx.7z-------4.311.135 bytes
LTT2.docx.arc------4.304.844 bytes
LTT2.docx.rar-------4.288.586 bytes
LTT2expand.rar----2.224.025 bytes
LTT2expand.7z-----1.128.672 bytes
LTT2expand.arc------867.204 bytes

Expanding file and the recompressing, can be increased compression.

In the case of backups made ​​in offices, consisting of thousands of Microsoft Office files, this procedure greatly reduce the size of backups.

[moisesmcardona]

I did a research on this a long time ago and I came to the same conclusion as you. In my case, I unzipped the docx and pptx and then compressed them with PAQ. Then, to restore the file I would extract the PAQ file then compress it with ZIP file.

[m^2]

It's a well known fact. I did a detailed benchmark some time ago and came to conclusion that 4x4 was faster and way stronger than the default, though my dataset was less than perfect. I think the benchmark should be available somewhere on this forum.