Nzma2.7z < 2025-2026 >

: While LZMA2 is generally superior, some users have noted that for certain highly compressible files (like ATTO bench test files), it can "fail" to compress efficiently in a single pass. Interestingly, compressing that same already-compressed file a second time can shrink it from nearly 40 KB down to just 600 bytes, suggesting quirks in how the algorithm identifies data filters.

One interesting piece about the method is its specialized efficiency with multi-threading. Unlike the original LZMA, LZMA2 can split large files into independent chunks (typically 256 MB or more), allowing it to utilize multiple CPU cores simultaneously for both compression and decompression. Key Technical Curiosities NZMA2.7z

: Some third-party tools have "abused" the 7z format by hiding Linux file attributes in unused bits of the metadata. While the official 7-Zip UI now tries to acknowledge these, they are not technically part of the official archive codebase. Quick Comparison: LZMA vs. LZMA2 Multi-threading Limited for large files High (splits into chunks) Compressed Data Poor with already-compressed data Better handling Speed Generally slower on modern CPUs Faster for 4+ threads Problem Extracting 7z Archives · Issue #73 - GitHub : While LZMA2 is generally superior, some users