: Using "Ultra" compression on large files requires significant RAM (sometimes over 8GB for a 512MB dictionary).
: If the archive is "long" and was interrupted during creation, the headers (stored at the end of the file) may be missing or corrupt. Key Technical Specs Unable to extract 7z archives with long paths #116 - GitHub : Using "Ultra" compression on large files requires
: Large archives, especially those created with fewer threads, can extract slowly. If it contains millions of small files, disk metadata overhead will significantly slow down the process. especially those created with fewer threads