A67zip -

In 7-Zip, the compression feature treats multiple files as a single continuous data stream, which often results in significantly higher compression ratios, especially when archiving many similar files. Key Benefits

Updating or adding a new file to an existing solid archive can be slower because the software may need to recompress a portion or all of the solid block. A67zip

Because 7-Zip can find patterns across different files rather than just within a single one, solid archives are usually much smaller than non-solid ones. In 7-Zip, the compression feature treats multiple files

This mode is most effective when your archive contains many files of the same type or with similar content, as it "consolidates" the redundancy. Important Trade-offs A67zip